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MDDULE I - MATTER AND CHEMICAL CHANGE 







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University of Alberta Libraries 


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■ MULTIMEDIA CD ■ 


■ Identifying Common Gases: Carbon Dioxide, Hydrogen, and Oxygen 

■ Investigating Chemical Reactions: Evidence of Chemical Change, Part 1 

■ Investigating Chemical Reactions: Evidence of Chemical Change, Part 2 

■ Corrosion of Iron 

■ Chemical Reactions: Generating or Absorbing Heat? 

■ Generator 

■ Mousetrap-Powered Cars 

■ Reaction Time Java Applet 

■ Conservation of Momentum: Two-Mass, Inelastic Collision 

■ Changing Momentum Quickly: Frontal Crash Test 

■ Energy Consumption 

■ Efficiency 






MDDULE i - MATTER AND CHEMICAL CHANGE 



Science 24 

Module 1 : Matter and Chemical Change 
Student Module Booklet 
Learning Technologies Branch 
ISBN 0-7741-2564-0 

The Learning Technologies Branch acknowledges with appreciation the Alberta Distance Learning Centre and 
Pembina Hills Regional Division No. 7 for their review of this Student Module Booklet. 


This document is intended for 

Students 

/ 

Teachers 

/ 

Administrators 


Home Instructors 


General Public 


Other 




You may find the following Internet sites useful: 

• Alberta Learning, http://www.learning.gov.ab.ca 

• Learning Technologies Branch, http://www.learning.gov.ab.ca/ltb 

• Learning Resources Centre, http://www.lrc.learning.gov.ab.ca 


The use of the Internet is optional. Exploring the electronic information superhighway can be 
educational and entertaining. However, be aware that these computer networks are not censored. 
Students may unintentionally or purposely find articles on the Internet that may be offensive or 
inappropriate. As well, the sources of information are not always cited and the content may not 
be accurate. Therefore, students may wish to confirm facts with a second source. 


ALL RIGHTS RESERVED 

Copyright © 2004, the Crown in the Right of Alberta, as represented by the Minister of Learning, Alberta Learning, 10155-102 Street, 
Edmonton, Alberta T5J 4L5. All rights reserved. Additional copies may be obtained from the Learning Resources Centre. 

No part of this courseware may be reproduced in any form, including photocopying (unless otherwise indicated), without the written 
permission of Alberta Learning. This courseware was developed by or for Alberta Learning. Third-party content has been identified 
by a © symbol and/or a credit to the source. Every effort has been made to acknowledge the original source and to comply with 
Canadian copyright law. If cases are identified where this effort has been unsuccessful, please notify Alberta Learning so corrective 
action can be taken. 

THIS COURSEWARE IS NOT SUBJECT TO THE TERMS OF A LICENCE FROM A COLLECTIVE OR 
LICENSING BODY. 


UNIVERSITY LIBRARY 

mth/CLien-V nr Al nrrvr,, 


Welcome to 


SCIENCE 2 A 


Mo4 Li Ie One 

Science 24 contains four modules. 

You should work through the modules in order (from 1 to 4) 
because concepts and skills introduced in one module will 
be reinforced, extended, and applied in later modules. 



MODULE 1 

■ MATTER AND CHEMICAL CHANGE 






10 Module Overview 


12 


Section 1: 

13 

17 

20 

24 

28 


Useful Chemistry 

Lesson 1: Chemistry Then and Now 
Lesson 2: Plastics, Polymers, and Alloys 
Lesson 3: Chemistry at Home 
Lesson 4: Chemistry at Work 

Section 1 Review 


29 


Section 2: Common Reactions in Our Lives 


30 Lesson 1: Useful Reactions 
35 Lesson 2: The Changes That Occur 
40 Lesson 3: Evidence That Change Has Occurred 
44 Lesson 4: Energy and Chemical Reactions 

49 Section 2 Review 


50 



Section 3: 

51 

53 

59 

62 

67 


Types of Chemical Reactions 

Lesson 1 : Word Equations 

Lesson 2: Types of Reactions 

Lesson 3: Formulas for Common Compounds 

Lesson 4: Chemical Equations 

Section 3 Review 





69 Section 4: Reactions and the Environment 

70 Lesson 1: Fossil Fuel Combustion 

76 Lesson 2: Acid-Base Reactions 

79 Lesson 3: Corrosion of Iron 
82 Lesson 4: Solving the Problem of Corrosion 

84 Section 4 Review 

85 Module Summary 

87 Appendix 

88 Glossary 

89 Suggested Answers 
135 Image Credits 

T1 Template for Which Dish Detergent Is Best? 



Course 


Features 


The Science 14-24 Program 

The Science 1 4-24 program is designed for students whose needs, interests, 
and abilities focus on basic science understanding. This course sequence 
emphasizes scientific and related technological knowledge and skills that will 
enable you to understand and interpret the world around you. If you successfully 
complete each of these five-credit courses, you will meet the minimum 
requirement in science for an Alberta high school diploma. 


To support your development of scientific literacy, the Sciencel 4-24 program 
provides a foundation of learning experiences to address the critical aspects of 
science and its applications. The following four foundations provide the general 
direction for Science 14 and Science 24: 

• Science, Technology, and Society (STS): You will develop an 
understanding of the nature of science and technology, the relationships 
between science and technology, and the social and environmental contexts 
of science and technology. 

• Knowledge: You will extend your knowledge and understanding of 
concepts in life science, physical science, and Earth and space science. 

• Skills: You will develop the skills required for scientific and technological 
inquiry, for solving problems, for communicating scientific ideas and results, 
for working with others, and for making informed decisions. 

• Attitudes: You will be encouraged to develop attitudes that support the 
responsible acquisition and application of scientific and technological 
knowledge to the mutual benefit of self, society, and environment. 

Consult your teacher or counsellor for information on Science 14 and Science 24. 
Also, if you have access to the Internet, you can find out more about Science 14, 
Science 24, and high school requirements at the Alberta Learning website. 

http://www.learning.gov.ab.ca 



6 


Science 24 


Overview of Science 24 


Science 24 is the final course in the Science 14-24 course sequence. In this 
course you will deal with four different areas of science: applications of matter 
and chemical change; common energy conversion systems; disease defence 
and human health; and motion, change, and transportation safety. 

This Science 24 course consists of four modules. Each module consists of one 
Student Module Booklet and two Assignment Booklets. The booklet you are 
presently reading is called a Student Module Booklet. It will show you, step by 
step, how to advance through each module. 



MODULE 1 

■ MATTER AND CHEMICAL CHANGE 


ASSIGNMENT BOOKLET IB 


ASSIGNMENT BOOKLET 2A 


MODULE 2 

-ENERGY TRANSFORMATIONS 


ASSIGNMENT BOOKLET 2B 


ASSIGNMENT BOOKLET 3A 


MODULE 3 

> DISEASE DEFENCE AND HUMAN HEALTH 


ASSIGNMENT BOOKLET 3B 


ASSIGNMENT BOOKLET 4A 


MODULE A 

■ SAFETY IN TRANSPDRTATIDN 


ASSIGNMENT BOOKLET 4B 


Resources 


Textbook 

To complete the course, you will need the textbook Science. Connect 2. 

Multimedia 

Attached to the inside cover of the textbook and to Module 1 of this course are 
multimedia CDs. These CDs contain multimedia segments designed to help you 
better understand particular concepts presented in this course. Ask your 
teacher, friend, or family member if you need help using these CDs. 


Science 24 


7 


Looseleaf Binder or Notebook 


Because response lines are not provided in the Student Module Booklets, you 
will need a looseleaf binder or notebook to answer questions and complete 
charts. It’s important to keep your lined paper handy as you work through the 
material and to keep your answers together in a binder for review purposes later. 

Materials and Apparatus 

The modules include numerous science activities and investigations that require 
materials and apparatus. A lab kit is not needed to complete this Science 24 
course. Many of the activities and investigations are set up so you can complete 
them using common household materials. Some investigations, however, do 
require lab material and apparatus. These investigations are set up with a Part A 
and a Part B. If you have access to a supervised laboratory facility, you may 
complete Part A of these investigations. If you do not have access, Part B will 
provide you with an alternate pathway. 

LearnAlberta.ca 

LearnAlberta.ca is a protected digital learning environment for Albertans. This 
Alberta Learning portal, found at http://www.learnalberta.ca, is a place where 
you can support your learning by accessing resources for projects, homework, 
help, review, or study. 

For example, LearnAlberta.ca contains a large Online Reference Centre that 
includes multimedia encyclopedias, journals, newspapers, transcripts, images, 
maps, and more. The National Geographic site contains many current video 
clips that have been indexed for Alberta Programs of Study. The content is 
organized by grade level, subject, and curriculum objective. Use the search 
engine to quickly find key concepts. Check this site often as new interactive 
multimedia segments are being added all the time. 

If you find a password is required, contact your teacher or school to get one. 

No fee is required. 


Science 24 


Assessment and Feedback 


Each Student Module Booklet is divided into sections. Within each section, your 
work is grouped into lessons. Within the lessons, there are readings, activities, 
investigations, and questions for you to do. By completing these lessons, you 
will discover scientific concepts and skills, practise or apply what you have 
learned, and develop a positive attitude toward science. 

Suggested answers to the questions are provided in the Appendix of each 
Student Module Booklet. They provide you with immediate feedback to the 
questions you complete in the lessons. 

At several points in the Student Module Booklet, you will be directed to the 
accompanying Assignment Booklets. Your grading in each module is based on 
the assignments you submit for assessment. You will be asked to submit each 
Assignment Booklet to your teacher once it is completed. Your teacher will then 
mark your Assignment Booklet and give you feedback as to how you are doing. 
Once you get your Assignment Booklet back, be sure you review your teacher’s 
comments and correct any errors you made. 

Visual Cues 

You will find many visual cues throughout this course. Colour is used to highlight 
the important terms that are defined in the Glossary of the Appendix. You will 
also encounter some icons in the margins. Read the following explanations to 
find out what each icon prompts you to do. 




Use the Internet. 

Note: Any website given 
is subject to change. 



Refer to the textbook. 



Refer to the 
multimedia CD given 
in Module 1 . 



Pay special attention 
to the safety precautions 
mentioned. 



Answer questions in the 
Assignment Booklet. 



Module Overview 



Have you baked a cake or made 
pancakes? If so, you have used a 
chemical reaction to your benefit. 
When baking a cake or making 
pancakes, substances combine 
chemically to form other substances 
one of which is a gas that makes 
cakes and pancakes light and fluffy. 


The chemical reaction in baking a cake or making pancakes is just one example 
of matter and chemical change. In fact, the coated baking pan and the cooking 
surface of the electric griddle are also products of chemical reactions. 

In this module you will examine chemical changes that occur in many parts of 
your daily life. You will study how chemistry is useful in everyday life and learn 
about common chemical reactions. You will then study several different types of 
chemical reactions and learn how to write word equations and formula 
equations for these reactions. Finally, you will explore chemical reactions that 
can affect the environment and identify any problems these reactions may 
cause. 


Science 24 


( 


MODULE 1 

■ MATTER AND CHEMICAL CHANGE 


■ USEFUL CHEMISTRY 


5 S 


■ COMMON REACTIONS IN OUR LIVES 

■ 5 


TYPES OF CHEMICAL REACTIONS 




REACTIONS AND THE ENVIRONMENT ■ 


\ 


C 


El 


ASSIGNMENT BOOKLET IA 


J 


Z7 



Assessment 

This module, Matter and Chemical Change, has four section assignments. The 
mark distribution is as follows: 


Assignment Booklet 1A 



Section 1 Assignment 

29 

marks 

Section 2 Assignment 

32 

marks 

Assignment Booklet IB 



Section 3 Assignment 

35 

marks 

Section 4 Assignment 

24 

marks 

Total 

120 

marks 



Look around your home. What types of products do you have? Do you have 
items made from plastic? dry-chemical batteries, like those commonly found in 
remote controls or portable stereos? pots and pans coated with a stick-resistant 
material? Are your clothes made of natural fibres, like wool and cotton, or are 
they made of synthetic fibres, like nylon? What are your music CDs and CD 
players made from? 


In this section you will see how useful chemistry is and how materials people 
use have changed over the past 100 years because of chemistry. You will learn 
about changes involved in cooking, cleaning, and gardening. You will also 
investigate the use of chemicals in the workplace and interpret safety 
information for the workplace and for home. 



Turn to pages 4 and 5 of the textbook. Read the introduction to “Chapter 1 : 
Useful Chemistry.” Pay particular attention to “What You Will Learn,” “Why It Is 
Important,” and “Skills You Will Use” on page 5. These will give you a quick 
overview of the material you will cover in this section. 






12 


Science 24 • Module 1 • Section 1 



Chemistry Then and Now 



PROVINCIAL ARCHIVES OF ALBERTA/PAA-030504 


Do you take many of the products and processes that provide convenience in 
your everyday life for granted? It wasn’t long ago that many of the items used in 
farming, in cooking, in clothing, and in recreation did not exist. In this lesson you 
will identify some of the common items that are available today. You will 
compare these to what was available 1 00 or more years ago. 

Farming 100-150 years ago involved mostly manual labour. Today, much of the 
labour on farms has been replaced by chemical and technological advances. 



Turn to page 6 of the textbook and read “Chemistry on the Farm.” Also, read the 
information in Figure 1.1 and “Did You Know?” carefully. 


1 . Describe how technological advances have changed farming today 
compared to farming 150 years ago? 

2. Describe how chemical advances have changed farming today compared to 
farming 150 years ago? 


Science 24 • Module 1 • Section 1 


13 




3. State two benefits chemical and technological 
advances in farming have provided. 

4. Why are manufactured fertilizers more effective 
than natural fertilizers? 


5. What benefits do natural fertilizers provide to the 
soil that manufactured fertilizers do not? 

6. Why do farmers need to handle a pesticide like Dursban with care? 

7. How can farmers learn about the precautions required when handling 
pesticides? 


Check your answers on pages 89 and 90 of the Appendix. 

Chemistry has also made improvements over the past 100 years in cleaning 
products. Back then, people on farms used animal fat to make their own soap 
for washing. Today, there are wide varieties of soaps, some made with animal 
fat and some made with plant oils. 

Turn to page 7 of the textbook and read “Chemistry for Cleaning.” 

8. What improvements have been made to soaps over the past 100 years? 

9. How does soap help water clean away grease even though grease is not 
soluble in water? 


Check your answers on page 90 of the Appendix. 






Science 24 • Module 1 • Section 1 




I 

How Can You Make Soap from Natural 
Substances? 

Read the entire activity on page 7 of the textbook. 

If you have access to a supervised laboratory, 
do Part A. If you do not have access to a 
supervised laboratory, do Part B. 

Part A 

Refer to the list of required materials, and follow the instructions in 
“What to Do” carefully. Pay special attention to the safety 
precautions mentioned. 

10. Use the soap you make to wash your hands. Does it feel and smell 
different than the soaps of today? 

Check your answer on page 90 of the Appendix. 

Part B 

Use the Internet or your local library to research soap making. Here is 
one site that discusses old-time soap making: 

http://www.waltonfeed.com/old/soaphome.html 

There are numerous sites about modern, home-based soap making. 

1 1 . Write a brief report (one or two paragraphs) on what you learned 
about soap making. 

Check your answer on page 90 of the Appendix. 

V J 






Science 24 • Module 1 • Section 1 







15 


The major change chemistry has made to people’s lifestyles is in the area of 
synthetic material for clothing. Although natural fibres (like cotton, linen, silk, 
and wool) are still popular choices in most clothes people wear, these fibres are 
often mixed with a synthetic fibre, called polyester. The polyester fibre adds 
strength to the natural fibres. 

Items in sports clothing and sports equipment, especially, have greatly benefited 
from advances in chemistry over the past 100 years. 

Turn to page 8 of the textbook and read “Chemistry and Synthetics.” 

12. Name five sports items that use synthetic fibres or synthetic material. 

13. Why is polyester a good material for sports clothing? 

1 4. What was nylon first made from? 

15. Answer “Try This!” at the bottom of page 8 of the textbook. Use a 
magnifying glass or microscope to observe the fibre strands. 



Check your answers on pages 90 and 91 of the Appendix. 



You have now completed the concepts for this lesson. 
Do the following questions to review what you studied 


16. Complete questions 1, 2, and 3 of “Check Your Understanding” on page 9 
of the textbook. 



Go to pages 1 and 2 of Assignment Booklet 1 A and answer questions 1 to 4. 


Science 24 • Module 1 • Section 1 


Plastics, Polymers, and Alloys 


j 

| synthetic 
polymer: 
any one of a 
| number of 
i long-chained 
compounds 
made in a 
laboratory 

alloy: a 
mixture of 
' two or more 
j metals; 
j looks like 
i one metal 



Another major change brought about by 
chemistry is the development of synthetic 
polymers and alloys. Some polymers, such 
as the silk threads in a spider’s web and the 
sap from a rubber tree, are made naturally. 
Over the past 75 years chemists have made 
many synthetic polymers. 




Turn to page 9 of the textbook and read the introductory paragraphs of 
“Plastics, Polymers, and Alloys.” Study Table 1.1 and Figure 1.3 carefully. 


1 . What is a polymer? (See Figure 1 .3.) 


2. What are most synthetic polymers commonly known as? 

3. Name four types of synthetic polymers. 

4. Why are lenses for glasses made from a polymer better than those made 
from glass? 



Check your answers on page 91 of the Appendix. 


Science 24 • Module 1 • Section 1 




In the next activity you can make a polymer 
using substances found at home. Complete thi 
activity if you can get the required substances, 





Make Your Own Polymer 

Read the entire activity on page 1 0 of the textbook. 

Follow the instructions in “What to Do.” Pay special attention to the 
safety precautions mentioned. 

5. Answer questions 1 .b., 1 .c., 2, and 3 of “What Did You Find Out?” 

Ju* 

Check your answers on page 92 of the Appendix. 


Many products developed through advances in chemistry in the last 100 years 
are made of alloys. An alloy is a mixture of two or more metals resulting in what 
appears to be one metal. The alloy will have the properties of the original metals 
it was made from. Often, the properties of an alloy are different from those of its 
components. 

Turn to pages 10 and 1 1 of the textbook and read “Alloys.” 

6. Give an example of an alloy used for kitchen utensil 
Which substances make up this alloy? 

7. a. What is superplastic steel? 

b. State an advantage of superplastic steel. 

c. Where might superplastic steel be used? 





Science 24 • Module 1 • Section 1 


8. a. Which substances make up 14K yellow gold? 
b. Why is pure gold not used for jewellery? 

9. Complete “Try This!” on page 1 1 of the textbook. 


10. Read “Did You Know?” on page 1 1 of the textbook. 

a. Which substances make up brass? 

b. Name some items that are often made from brass. 






If you have access to the Internet, do “Internet Connect” on page 1 1 of the 
textbook. This site will expand on your knowledge of gold jewellery alloys. 



You have now completed the concepts for this lesson. 
Do the following questions to review what you studied. 



1 1 . Answer questions 2 and 3 of “Check Your Understanding” on page 1 1 of the 
textbook. For question 2. a., you may need to check the labels of various 
types of clothing. 



Check your answers on page 93 of the Appendix. 



Go to pages 2 and 3 of Assignment Booklet 1 A and answer questions 5 to 9. 


Science 24 • Module 1 • Section 1 


19 


Chemistry at Home 


chemical 
reaction: a 
transformation 
that occurs 
when 

substances 
react, forming 
one or more 
new 

substances 

with 

properties 
different from 
the original 
substances 




If you were to look into the various cupboards in your home, you would find 
products that contain various chemicals for cleaning as well as for cooking. 
Cleaning products contain chemicals that break down dirt and grease and help 
make cleaning easier. Some cooking products contain chemicals that react 
when combined with other chemicals. These chemical reactions help in the 
cooking process. 

Turn to page 1 2 of the textbook and read the introductory paragraphs of 
“Chemistry at Home.” 

1 . Name three types cleaning products used in the home. 

2. Which chemical is often present in drain cleaners? 

3. How do drain cleaners clear clogged drains? 



Check your answers on page 93 of the Appendix. 


20 


Science 24 • Module 1 • Section 1 





Different chemicals are used to clean different items. 
Check out Table 1 .2 on page 1 2 of the textbook to 
see which chemicals are used for a given item. 


4. Name the chemical used to clean a clogged steam iron. Describe how this 
chemical works. 

5. How does acetone remove nail polish? 



Check your answers on page 93 of the Appendix. 



Read the information in Figure 1 .6 on page 12 of the textbook, and study the 
HHPS symbols shown. Note: This information has since been updated by 
Health Canada. The information symbols (poisonous, flammable, etc.) shown in 
Figure 1 .6 are still used. The three shapes (octagon, diamond, and triangle) for 
the degree of severity, however, are no longer used. Presently, only two shapes 
are used: the octagon and the triangle. The octagon shows that the warning 
refers to the contents of the container, and the triangle shows that the warning 
refers to the container itself. Because some containers use a propellent that may 
explode when heated, a warning label is now given regarding the container. 


6. Which HHPS symbols appear on the product in the photograph? 



Science 24 • Module 1 • Section 1 


21 


7. Draw the HHPS symbol for each of the following situations. 

a. The contents of a product are corrosive. 

b. The contents of a product are flammable. 

c. The container of a product is explosive. 



Check your answers on page 93 of the Appendix. 


Read “Try This!” and “Did You Know?” on page 12 of the 
textbook. They will provide you with some information on other 
chemicals that may be used around the home. 

8. Which two substances can be used to make furniture 
polish? 

9. How may the foaming action of hydrogen peroxide help 
heal a cut? 





HEC 


Check your answers on page 93 of the Appendix. 


Chemicals and chemical reactions are important in cooking as well. Turn to 
page 13 of the textbook and read “Chemistry and Cooking.” Then read the 
“Did You Know?” section about why stainless steel is commonly used in 
kitchens today. 

10. Why do bakers need some knowledge of chemistry? 

1 1 . Which ingredient is responsible for making bread rise? 

12. Which substance makes the bubbles in sponge toffee? 

13. Why shouldn’t you use aluminum utensils with citrus fruits or rhubarb? 

14. Complete “Try This!” on page 13 of the textbook. 



Check your answers on page 94 of the Appendix. 


Science 24 • Module 1 • Section 1 


Cooks and bakers measure ingredients, apply thermal energy, and cause 
chemical and physical changes to matter. In this way they are using chemistry 
every day. The next activity illustrates the chemistry involved in baking chocolate 
chip cookies. 




Investigation 

1-A: Chemist’s Recipe for Chocolate Chip Cookies 

Read the entire investigation on page 14 of the textbook carefully. 


Obtain the required ingredients and apparatus, and 
complete the activity as outlined in “What to Do.” Pay 

particular attention to the safety precautions 
given. 


4% 

,\ 


j!.r. 


Note: If you are working at home, have an adult 
help you complete this activity. 

15. How did the ingredients change through the 
combining and baking processes? 

16. What does this activity show? 


t 



f , 




. 

% 


w- ,* * 


CHEtK y° ur answers on P a 9 e 94 of the Appendix. 




Go to 


You have now completed the concepts for this lesson. To review what you 
covered, do the following questions. 

17. Answer questions 2 and 3 of “Check Your Understanding” on page 15 
of the textbook. 


eSd Check your answers on page 94 of the Appendix. 


Go to pages 3 and 4 of Assignment Booklet 1A and answer questions 10 to 13. 


Science 24 • Module 1 • Section 1 


23 



fS 


Chemistry at Work 

Have you ever worked at a swimming pool or golf course? Did you know that a 
working knowledge of chemistry is needed in these jobs? At a swimming pool, 
the chlorine level needs to be tested several times per day because additional 
chlorine may be needed. Other chemicals may also need to be added to the 
water. At a golf course, the fairways and greens may need to be sprayed for 
weeds several times a year. Fertilizers also need to be applied regularly. 


For more information on how chemistry is used at places of work, read the 
introductory paragraphs of “Chemistry at Work” on page 15 of the textbook. 

1 . Name four areas of work where a working knowledge of chemistry is needed. 

2. How are chemicals used in an automotive repair shop? 

3. How are chemicals used in a hair salon? 



The greens of a golf course need 
to be sprayed before winter with 
a special chemical to prevent 
molds from growing under the 
snow as spring approaches. 



Di4 you know? 1 


Check your answers on page 95 of the Appendix. 



24 


Science 24 • Module 1 • Section 1 



Chemistry is very important in hair styling. Even the pH of shampoo is important 
when washing your hair. Read the information presented in “Cosmetic 
Chemistry” on page 16 of the textbook. 


4. Before 1938, how did hair stylists remove the soap scum from hair after 
washing. 

5. How do shampoos add texture to your hair? 

6. According to the pH scale at the bottom of page 16, what is the pH of 
detergents? 

Check your answers on page 95 of the Appendix. 





1-B: Which Dish Detergent Is Best? 


Read the entire activity on page 1 7 of the textbook. 

Follow the instructions carefully, and complete the activity. 

Pay special attention to the safety precautions 
mentioned. 

If you are working at home, you may only be able to 
obtain two or three different detergents. That is okay. 

7. Identify the manipulated and responding variables. 

8. Identify variables that must be controlled. 



9. Write a lab report. Use the template given at the back of the Appendix. 


10. Answer questions 1 to 4 of “Evaluate.” 



Check your answers on pages 95 to 97 of the Appendix. 



Science 24 • Module 1 • Section 1 


25 


Another area in which chemistry has changed how things are done in the last 
100 years is that of cosmetics. There are hundreds of brands of make-up and 
facial creams available on the market today. Chemistry has played a large part in 
making more cosmetics available. 



Read “Make-up and Face Cream” on page 18 of the textbook. 

1 1 . How long have some cosmetics been around? 

12. How might chemistry help in producing cosmetics? 



Check your answers on page 97 of the Appendix. 


Di4 you know? 

It was common for Ancient Egyptians, both men and women, to use cosmetics. 
Some of the products consisted of beeswax as a base, just like in some 
cosmetics today; others, however, had lead-based compounds in them. If you 
have access to the Internet, you can search for more information on cosmetics 
in ancient Egypt by entering the words cosmetics and Egypt in any of the 
Internet’s search engines. 




If you have access to a supervised lab, you may wish 
to complete "Find Out Activity: Make a Skin Cream" 
on pages 1 8 and 1 9 of the textbook. 


Science 24 • Module 1 • Section 1 


You may recall information from Science 14 about how you can determine if 
materials are hazardous by looking at the WHMIS label on the containers. You 
may also recall that more detailed information about hazardous materials can be 
found on Material Safety Data Sheets (MSDS), which are provided with the 
products. 



Turn to page 19 of the textbook and read “The Key to Chemical Safety.” 
Familiarize yourself with the WHMIS symbols in Figure 1.13. 


13. How can you learn about the safety precautions required for a product you 
have not seen or used before? 

14. What does WHMIS stand for? 

15. What information might you find on the label of a hazardous product? 

16. When can ordinary table salt be a hazardous substance? 


17. Which symbol would be on the label of a container of a strong acid? 




CHEdK 


Check your answers on page 97 of the Appendix. 



You have now completed the concepts for this lesson. 
Do the following questions to review what you covered. 


18. Answer questions 1 and 2 of “Check Your Understanding” on page 19 of the 
textbook. 


at 


ChIcK y° ur answers on P a 9 e 97 of the Appendix. 

Go to pages 4 and 5 of Assignment Booklet 1 A and answer questions 14 to 18. 


Science 24 • Module 1 • Section 1 


27 




In this section you saw how useful chemistry is 
and how materials used today have changed 
over the past 100 years because of chemistry. 
You especially examined the changes involved 
in cooking, cleaning, and gardening. You then 
investigated the use of chemicals in the 
workplace and interpreted safety information 
for the workplace and for home. 

You have seen, first hand, how chemistry is 
involved in the everyday products you use. 
Hopefully, you now have a better appreciation 
for chemistry; it is quite useful, and it has 
provided many of the conveniences and 
products you take for granted today. 



You have now completed the concepts for this 
section. To review what you covered, answer 
the following “Chapter 1 Review” questions on pages 20 and 21 of the textbook. 
If necessary, go back and read over parts of this section as you answer the 
questions. 


1 . Answer questions 3 and 5 of “Reviewing Key Terms.” 

2. Answer question 10 of “Understanding Key Ideas.” 

3. Answer question 15 of “Developing Skills.” 

4. Answer question 19 of “Critical Thinking.” 



Check your answers on page 98 of the Appendix. 


28 


Science 24 • Module 1 • Section 1 



■ 


Have you taken a roll of film to be developed? Did you know that a chemical 
reaction occurs when developing film? It occurs when the information stored on 
the film is changed into the shapes and colours of the picture you took with your 
camera. Chemical reactions occur in many everyday situations, such as 
cooking, cleaning, driving to school or work, and even eating. 


In this section you will investigate some of the reactions that occur around you 
every day and discover just how useful these reactions are to you. You will see 
how substances change in a chemical reaction and describe different types of 
reactions. You will then learn to identify the evidence that proves that a reaction 
has in fact occurred. You will also discover that energy is either absorbed or 
released in a chemical reaction. 



Turn to pages 22 and 23 of the textbook and read the introduction to 
“Chapter 2: Common Reactions in Our Lives.” Pay particular attention to “What 
You Will Learn,” “Why It Is Important,” and “Skills You Will Use” on page 23. 
These will give a quick overview of the material you will be studying in this 
section. 


Science 24 


Module 1 • Section 2 


29 



Useful Reactions 


Every day, many natural events 
and human activities involve 
chemical reactions. Fruit, for 
example, ripens due to a 
chemical reaction; the toast you 
make turns brown due to a 
chemical reaction; school buses 
are powered by the result of a 
chemical reaction. All these 
reactions, and more, are very 
important to people’s everyday 
lives. 



Turn to page 24 of the textbook. 
Read the introductory information 
of “Useful Reactions.” 


1 . What occurs during a 
chemical reaction? 


2. The reaction that powers the 
space shuttle is a simple 
reaction. What are the 
reactants and products for this 
reaction? 



3. What are the reactants and products when you take an antacid for an upset 
stomach? 


4. How do you know a chemical reaction occurs when bananas ripen? 

5. Explain how bananas ripen. 


' Check y° ur answers on page 99 of the Appendix. 


30 


Science 24 • Module 1 • Section 2 



Cleaning and cooking make use of chemical reactions. 
Read “Whitening Whites” and “Baking Bread” on pages 
24 and 25 of the textbook. You will learn more about 
chemical reactions in these areas. 


6. Which substances are the active whitening 
ingredients in bleach? 



7. Which common element is present in these whitening ingredients? 


8. Describe the reactions that cause bread dough to rise. 

9. What gives freshly baked bread its delicious flavour? 

10. Read “Did You Know?” on page 25. Describe the process of digesting 
carbohydrates, fats, and proteins that involves enzymes. 




Check your answers on page 99 of the Appendix. 



If you’ve been to a swimming pool, particularly an indoor swimming pool, you 
probably noticed a distinct odour of chlorine in the air. To see how chlorine 
works to kill micro-organisms in a swimming pool, read “Swimming Pool Scent” 
on page 25 of the textbook. 


1 1 . Which substance is produced when chlorine is added to water? 



Check your answer on page 99 of the Appendix. 


Science 24 • Module 1 • Section 2 


31 


People who own swimming pools 
need to know how to keep the water 
clean. The amount of chlorine required 
to keep a swimming pool safe is 
measured in parts per million (ppm). A 
level of at least 1 ppm of free chlorine 
is required to keep a swimming pool 
clean. In addition, the pH of the water 
must be maintained between 7.2 and 
7.6 for the chlorine to work properly. 

If you have access to the Internet, you 
can find more information on the 
chemistry of swimming pools. Enter 
the words chlorine and pool into any 
of the Internet’s search engines to find 
numerous sites on swimming pool 
maintenance. 

12. What protection should people 
wear when working with chlorine? 



13. Many kitchen and bathroom 

cleaners contain chlorine. Obtain a number of cleaners that contain chlorine. 
List the warning symbols on these containers. 



Check your answers on page 99 of the Appendix. 



When making bread, the reaction of yeast and 
glucose produces carbon dioxide. Many chemical 
reactions produce gases like carbon dioxide, 
hydrogen, and oxygen as one of the products. The 
next investigation will show you how to identify 
the presence of each of these gases. 


\ 


Science 24 • Module 1 • Section 2 


2-A: Identifying Common Gases 

Turn to pages 26 and 27 of the textbook and read the entire investigation. 
14. Make a prediction for Part 1 , Part 2, and Part 3. 



, 

i 





Check your answer on page 100 of the Appendix. 


If you have access to a supervised laboratory, do Part A. If you do not have 
access to a supervised laboratory, do Part B. 

Part A 

Complete the entire investigation as directed in the procedure on pages 26 

and 27 of the textbook. Pay careful attention to the safety precautions 
mentioned. 



15. Answer the following on page 27 of the textbook. 

a. questions 1 and 2 of “Analyze” 

b. question 3 of “Conclude and Apply” 



Check your answers on page 100 of the Appendix. 


Science 24 • Module 1 • Section 2 


33 


Part B 


Insert the Science 24 Multimedia CD into your computer. View the segment 
“Identifying Common Gases: Carbon Dioxide, Hydrogen, and Oxygen.” You will 
observe a demonstration of the reactions in this investigation. Use the 
information in this segment to answer question 15 in Part A. 




16. Complete “Try This!” on page 27 of the textbook. Pay special attention to 
the following safety precautions: 

• Stand the candle in an appropriate candle holder before lighting. 

• Keep the beaker or glass above the flame. 

• Extinguish the flame immediately after you complete the activity. 


17. Answer questions 1 , 3, and 4 of “Check Your Understanding” on page 28 of 
the textbook. 


Check your answers on page 101 of the Appendix. 


Go to pages 6 and 7 of Assignment Booklet 1 A and answer questions 1 to 7. 




Check your answer on page 100 of the Appendix. 


You have now completed the concepts for this lesson. 
Do the following questions to review what you coverec 




Science 24 • Module 1 • Section 2 




B H 




The Changes That Occur 


Study the diagram on the right. Two substances are mixed 
in a beaker. How do you know that a chemical reaction 
has occurred? The change in colour that occurs 
where the two liquids mix indicates that a reaction 
has occurred. The changes that occur when you 
mix substances together tell you that a reaction 
has occurred. In a chemical reaction, the 
substances you start with are not the same 
substances you end up with. 


H 


/i 





Bottled Sunshine 

Read the entire activity on page 23 of the textbook. 



If you have access to a supervised laboratory, do Part A. If you do not 
have access to a supervised laboratory, do Part B. 



Part A 

Complete the activity as directed in “What to Do.” Pay careful 
attention to the safety precautions mentioned. 

1 . Answer questions 1 and 2 of “What Did You Discover?” 



Check your answers on page 101 of the Appendix. 


Science 24 • Module 1 • Section 2 


35 




Part B 

Use the following diagrams to answer questions 2 and 3. 

step 1: 



36 


Science 24 • Module 1 • Section 2 



2. How do you know energy was released in step 2? 

3. What evidence of a chemical change do you see in step 3? 




ECI 


Check your answers on page 101 of the Appendix. 


You have just seen evidence of changes that occur in some chemical reactions. 
Now, turn to page 28 of the textbook and read “The Changes That Occur.” 

4. The substances present before a reaction are called the 

5. The substances present after a reaction are called the 

6. List the three main indicators that a chemical reaction has occurred. 

7. Are there any other indicators of a chemical reaction? 

8. What evidence is there that a reaction has occurred in Figure 2.6? 



Check your answers on pages 101 and 102 of the Appendix. 


Science 24 • Module 1 • Section 2 


37 



Reactions are classified into several types. In Lesson 1 of this section, you did 
an activity involving a burning candle. This is a combustion reaction. Also, recall 
from Science 14 that when an acid is added to a base, the resulting solution 
may be a neutral solution. This type of reaction is called a neutralization 
reaction. 

Turn to page 29 of the textbook and read “Combustion and Neutralization.” 

9. A chemical reaction in which a fuel is burned in the presence of oxygen is 
called a reaction. 


10. The products of burning a candle in the presence of oxygen are 

and 

1 1 . Chemical reactions involving an acid added to a base to produce a new 

compound and water are called reactions. 

12. What area of homemaking often involves acid-base reactions? 

13. Taking an antacid is a common neutralization reaction. In this reaction you 
take a base to neutralize the excess acid in your stomach. 

a. What is the name of the base commonly found in antacid medication? 


b. Write out the word equation for the neutralization of stomach acid with 
an antacid. 

c. Which compounds are formed? 


14. Toothpastes contain various ingredients to help clean your teeth. Read the 
information in “Did You Know?” on page 29 of the textbook. List the 
ingredients in your toothpaste. How many of the ingredients in your 
toothpaste match those given in the “Did You Know?” section? 



38 


Science 24 • Module 1 • Section 2 



~\ 



An Invisible Gas Made Visible 

Read the entire activity on page 30 of the textbook to get a general idea. 

Follow the instructions in “What to Do” carefully to complete the activity. 

Pay special attention to the safety precautions mentioned. Be sure 
to extinguish the candle once you have completed the activity. 

If you are working at home, you can use a measuring cup instead of a 
graduated cylinder. Also, you can use a glass or a clean, 600-mL, plastic 
pop bottle instead of an Erlenmeyer flask. Be careful not to bring the 
plastic pop bottle too close to the candle flame. 


15. Complete textbook questions 1 , 2, and 3 of “What Did You Find 
Out?” 





If you have access to the Internet, do “Internet Connect” on page 30 of the 
textbook. You will investigate the chemical reaction 
that occurs in a hydrogen fuel cell. 


You have now completed the concepts for this lesson. 
Do the following questions to review what you studied. 


16. Answer questions 1 , 2, and 3 of “Check Your 
Understanding” on page 30 of the textbook. 





Check your answers on page 103 of the Appendix. 


Go to pages 7 and 8 of Assignment Booklet 1 A and answer questions 8 to 1 1 . 


Science 24 • Module 1 • Section 2 


39 



Evidence That Change Has Occurred 



Have you been amazed by the brilliant colour of the leaves on deciduous trees in 
the fall? The change in colour of the leaves is caused by the absence of a 
chemical reaction. Leaves change colours when days get shorter and 
chlorophyll is no longer produced. Without the green chlorophyll present, the 
pigments already present in the leaves show through. The change in colour of 
leaves is evidence that a chemical reaction is no longer occurring. 



Turn to page 31 of the textbook. Read the introductory paragraphs of “Evidence 
That Change Has Occurred.” 


1 . Describe a chemical change that occurs in nature. What is the evidence that 
a chemical change has occurred? 


2. What evidence of a chemical change is shown in Figure 2.7. 



Check your answers on page 103 of the Appendix. 


40 


Science 24 • Module 1 • Section 2 


b\ If you have access to the Internet, you may wish to go to the following site for 
information on chemical reactions: 

http://www.ric.edu/ptiskus/chemical 


You may also enter the words spectacular chemical reactions in any of the 
Internet’s search engines. 


When scientists do experiments in chemistry, they look for 
evidence of chemical change. In Investigation 2-B you will 
do a number of experiments in which you look for evidence 
of chemical change. 




2-B: Investigating Chemical Reactions 



Turn to pages 32 and 33 of the textbook and read the entire investigation to get 
a general idea of what you will be doing. 



Science 24 • Module 1 • Section 2 



41 


3. Predict what evidence you might see for each reaction. 


:cSk Check your answer on page 103 of the Appendix. 

If you have access to a supervised laboratory, do Part A. If you do not have 
access to a supervised laboratory, do Part B. 

Part A 

Complete the investigation as directed in the textbook. Follow the procedure 
carefully, and pay special attention to the safety precautions mentioned. 

4. Copy and complete the table on page 32 of the textbook. 

5. Answer the following on page 33 of the textbook. 

a. questions 2 and 3 of “Analyze” 

b. question 5 of “Conclude and Apply” 

c. question 6 of “Extend Your Skills” 



Check your answers on pages 104 and 105 of the Appendix. 


Part B 


Insert the Science 24 Multimedia CD into your compi ' 
View the segments “Investigating Chemical 
Reactions: Evidence of Chemical Change, Part 1 ” 



and “Investigating Chemical Reactions: Evidence 
of Chemical Change, Part 2.” You will observe a 
demonstration of the reactions in this 


investigation. Use the information in these 
segments to answer questions 4 and 5 in Part A. 



Science 24 • Module 1 • Section 2 




Turn to page 34 of the textbook and read the 
information in “Evidence of Chemical Change.” 

6. List five pieces of evidence that show that a 
chemical change has occurred. 


7. Give an example where a colour change is 
the evidence of the reaction. 


8. Give an example where bubbles appear 
during the reaction. 

9. What do you call the solid that forms as a 
result of combining two chemicals? 



Check your answers on pages 105 and 106 of the Appendix. 


r 




You have now completed the concepts for this lesson. 
Do the following questions to review what you studied. 




10. Answer question 2 of “Check Your Understanding” on page 34 of the 
textbook. 





Check your answer on page 106 of the Appendix. 

Go to pages 8 and 9 of Assignment Booklet 1 A and answer questions 12 to 16. 


Science 24 • Module 1 • Section 2 


43 


Energy and Chemical Reactions 



WORLD FAMOUS SALES OF CANADA 


If you have used a flashlight, watched fireworks, used a hot or cold pack, or sat 
around a campfire, you have seen chemical changes that involve energy. The 
previously mentioned activities involve energy changes that are obvious. All 
chemical changes involve some sort of energy change. 

To learn about energy changes, read the first three paragraphs of “Energy and 
Chemical Reactions” on page 35 of the textbook. 

1 . Which chemical reaction has a nearly unnoticeable energy change? 

2. Energy from burning gasoline in a car engine results mainly in which two 
types of energy? 



Check your answers on page 106 of the Appendix. 


Science 24 • Module 1 • Section 2 




exothermic 
reaction: a 
chemical 
reaction in 
which thermal 
energy (heat) 
is released 



endothermic 
reaction: a 
chemical 
reaction in 
which thermal 
energy (heat) 
is absorbed 


Chemical reactions are separated into two types: exothermic reactions and 
endothermic reactions. Exothermic reactions release heat to the surroundings; 
endothermic reactions absorb heat from the surroundings. You are most likely 
more familiar with exothermic reactions. 

Read the last two paragraphs of “Energy and Chemical Reactions” on page 35 
of the textbook. Study Figure 2.12 carefully. 

3. Give two examples of an exothermic reaction and two examples of an 
endothermic reaction. 



Check your answer on page 106 of the Appendix. 


Insert the Science. Connect 2 Student Multimedia CD into your computer, and 
double-click “Menu.” Once the menu appears, click on the applet “Chemical 
Reactions.” For now, only view Part 3: Signs of a Chemical Reaction. The 
remaining parts of this applet will be completed in Section 3 of 
this module. This part will provide more information on 
exothermic and endothermic reactions. Carefully follow the 
instructions, and answer the following questions as you 
proceed through this part of the applet. 

4. What evidence proves that the reaction that sends 
the space shuttle into space is exothermic? 

5. What evidence proves that the reaction that 
causes the flask to stick to the stool is 
endothermic? 

6. a. What evidence proves that a reaction has 

occurred when molten sodium is 
combined with chlorine gas? 

b. What product is formed? 



c6§D Check your answers on pages 106 and 107 of the Appendix. 


Science 24 • Module 1 • Section 2 


45 



Have you ever used a hot or cold pack? If so, you know that a hot pack provides 
energy to warm up your hands or feet and a cold pack takes away heat energy 
to provide soothing relief to an injured area of your body. The next investigation 
will have you compare different chemicals to determine which makes the best 
hot pack and which makes the best cold pack. 




2-C: Hot Packs and Cold Packs 

Turn to page 36 of the textbook and read the entire investigation. 

Here are some suggested modifications to the materials and instructions: 


• Mix each chemical with water in a Styrofoam cup, and measure the 
temperature change. 


• After you have completed the part of the investigation using the Styrofoam 
cups, add 50 ml_ of water and 50 g of chemical to a plastic bag and feel 
the warmth or cold through the bag. Repeat for each chemical. 


If you have access to a supervised laboratory, do Part A. If you do not have 
access to a supervised laboratory, do Part B. 


46 


Science 24 • Module 1 • Section 2 


Part A 



Follow the instructions in “Design Criteria” and “Plan and Construct.” Pay 

special attention to the safety precautions mentioned. 

Use 10 ml_ of water for 5 g of each chemical. Mix each chemical thoroughly 
after adding to the water. Record the initial temperature and the temperature of 
each chemical and water mixture after 30 s, 1 min, 2 min, and 3 min. 


7. Write a procedure for how to compare the chemicals provided. 

8. Copy and complete the following table. 





calcium chloride 



sodium chloride 



sodium acetate 



ammonium chloride 




9. a. Answer questions 1, 2, 3.a., 3.b., and 4 of “Evaluate.” 

b. Which reactions are exothermic? Which reactions are endothermic? 



Check your answers on pages 107 and 108 of the Appendix. 


Part B 


If you are working at home, complete Investigation 2-C using only calcium 
chloride (sidewalk deicer) and sodium chloride as the chemicals to compare. 
Use 2 tablespoons (30 mL) of water and 1 teaspoon (5 mL) of each chemical. 
Mix each chemical and water mixture thoroughly. Record the temperature after 
30 s, 1 min, 2 min, and 3 min. 


Science 24 • Module 1 • Section 2 



47 


10. Write a procedure for how to compare the chemicals tested. 

1 1 . Copy and complete the following table. Note that the data for sodium 
acetate and ammonium chloride has been provided. 


HE ■■ 



calcium chloride 



sodium chloride 



sodium acetate 

24 

50 

ammonium chloride 

24 

7 


12. a. Answer questions 1, 2, 3. a., 3.b., and 4 of “Evaluate.” 

b. Which reactions are exothermic? Which reactions are endothermic? 


Check your answers on pages 108 and 109 of the Appendix. 





You have now completed the concepts for this lesson. 
Do the following questions to review what you covered. 


13. Answer questions 1 , 2, and 3 of “Check Your 
Understanding” on page 37 of the textbook. 





Check your answers on page 109 of the Appendix. 


Go to pages 9 and 10 of Assignment Booklet 1 A and answer questions 17 to 21 . 


48 


Science 24 • Module 1 • Section 2 



In this section you investigated some of 
the reactions that occur around you 
every day and discovered just how 
useful these reactions are. You saw 
how substances changed in a chemical 
reaction, and you described different 
types of reactions. You determined 
how to identify if a chemical reaction 
has occurred, and you saw that energy 
is either absorbed or released in a 
chemical reaction. 



You now know how hot packs and cold 
packs work. Have you had to use a hot 
pack or cold pack recently, personally experiencing the transfer of energy in a 
chemical reaction? 



You have now completed all of the concepts for this section. To review what you 
studied, answer the following “Chapter 2 Review” questions on pages 38 and 39 
of the textbook. If necessary, go back and read over parts of this section as you 
answer the questions. 

1 . Answer question 1 of “Reviewing Key Terms.” 

2. Answer questions 5, 6, and 8 of “Understanding Key Ideas.” 

3. Answer question 10 of “Developing Skills.” 

4. Answer question 14 of “Critical Thinking.” 



Science 24 • Module 1 • Section 2 


49 



Some chemical reactions can be very spectacular. Fireworks are an example of 
a spectacular reaction that produces light, heat, and sound energy. Other 
reactions aren’t as spectacular, such as those used to treat disease, purify 
water, or produce a wide variety of products for you to use. 

In this section you will learn how to represent chemical equations using words 
and chemical formulas. You will identify and describe different reactions and 
recognize chemical formulas for some commonly occurring compounds. You will 
discover why scientists use balanced chemical equations and how the Law of 
Conservation of Mass applies to chemical reactions. 



Turn to pages 40 and 41 of the textbook. Read the introduction to “Chapter 3: 
Types of Chemical Reactions.” Read over the points in “What You Will Learn,” 
“Why It Is Important,” and Skills You Will Use” on page 41 . These provide a brief 
overview of what will be covered in this section. 


50 


Science 24 • Module 1 • Section 3 



Word Equations 






All Reactants 


All Products 


Chemical reactions are often represented using word equations. A word 
equation describes the reactants and products of a chemical equation using 
the names of the chemicals. 

Turn to page 42 of the textbook. Read the introductory information in “Word 
Equations.” Then read “Writing Word Equations.” This will summarize what you 
have learned about chemical reactions thus far, and it will provide an 
introduction to writing word equations. 

1 . List the three things you have learned thus far about chemical reactions. 

2. Why do chemists use word equations to represent chemical reactions? 

3. Describe the standard format for writing a word equation for a chemical 
reaction. 

4. What is the purpose of the plus sign (+) in a word equation that represents 
a chemical reaction? 



JF 


Check your answers on page 1 1 1 of the Appendix. 


Science 24 • Module 1 • Section 3 


51 



8. Answer questions 1 .a. and 1 .b. of “Check Your Understanding” on page 43 
of the textbook. 




(£h!cK 1 ^ heck your answers on P a 9 e 1 12 of the Appendix. 

Go to page 1 of Assignment Booklet 1 B and answer questions 1 to 4. 


b. How many reactants and products are in this equation? 

7. a. Write the word equation for the addition of hydrochloric acid to mossy 
zinc. 


You are already familiar with a number of commonly occurring chemical 
reactions, such as the reaction for cellular respiration. Read “Word Equations for 
some Chemical Reactions” on page 43 of the textbook. Familiarize yourself with 
the word equations for some commonly occurring chemical reactions. 


5. a. Write the word equation for the process of cellular respiration. 


b. Write out how you read this equation? 


c. How many reactants and products are there in the word equation? 


6. a. Write the word equation for the reaction that makes caves in areas of 
limestone. 


You have now completed the concepts for this lesson. 
To review what you studied, do the following questions. 


b. 


How does the word equation describe what you would observe if you 
actually added hydrochloric acid to mossy zinc? 


Check your answers on page 1 1 1 of the Appendix. 


52 


Science 24 • Module 1 • Section 3 



Types of Reactions 


simple 
composition 
reaction: a 

reaction in 
which two or 
more elements 
combine to 
form a 
compound 

simple 

decomposition 
reaction: a 

reaction in 
which a 
compound is 
broken down 
into its 
elements 



When you study for school, do you put things that are similar together? Do you 
look for patterns when you try solving a mathematics problem? Similarly, in 
chemistry, you can group chemical reactions together according to particular 
patterns in which the reactions occur. 

The most common types of reactions fall into four groups. You have already 
studied two of these types of reactions— combustion reactions and 
neutralization reactions. The other two types of reactions that most common 
chemical reactions fall under are simple composition reactions and simple 

decomposition reactions. 



Turn to page 44 of the textbook and read “Simple Composition Reactions.” Here 
you will see why chemists group reactions together and what kinds of reactions 
belong to the group of simple composition reactions. 


1 . List two reasons why chemists use patterns to group reaction types. 


Science 24 • Module 1 • Section 3 


53 



2. a. Write the word equation for the reaction of magnesium and oxygen. 

b. Name the reactants and products in this reaction. 

c. How many elements are used as reactants? 

d. What happens to the reactants during this reaction? 

3. Describe, in words, the general form of a simple composition reaction. 

4. Write the general form of a simple composition reaction using the letters A 
and B. 

5. Are most simple composition reactions exothermic or endothermic? 

6. Why is it important to know if a reaction is exothermic or endothermic? 




Another type of chemical reaction is the simple decomposition reaction. In 
simple decomposition reactions, a compound is separated into its elements. 
You have seen this type of reaction in Section 2 when you looked at the 
electrolysis of water. This reaction requires energy to drive it. 

Turn to page 45 of the textbook and read “Simple Decomposition Reactions.” 

7. a. Write the word equation for the electrolysis of water. 


b. What is the reactant in this reaction? What are the products? 


8. In a simple decomposition reaction, the products are always 


9. Write the general form for a simple decomposition reaction using the letters 
C and D. 

10. Most decomposition reactions are endothermic. What does this mean in 
terms of energy for these reactions? 

1 1 . Describe how simple composition reactions compare to simple 
decomposition reactions. 


54 


Science 24 • Module 1 • Section 3 


12. Read “Did You Know?” at the bottom of page 45 of the textbook. How do 
chemists today protect themselves from the hazards that past 
experimenters, like Sir Humphry Davy, experienced? 



A simple composition reaction combines elements to form a compound, and a 
simple decomposition reaction breaks a compound apart its elements. In Part 1 
of the next investigation you will observe the results of a decomposition reaction 
in which hydrogen peroxide (H 2 0 2 ) reacts to produce water and oxygen. In 
Part 2 you will observe the results of a chemical reaction that can be useful at 
home. 



3-A: Making It and Tearing it Down: A Composition/ 
Decomposition Reaction 



Read the entire investigation on pages 46 and 47 of the textbook. Note: The list 
of materials includes a trace amount of magnesium dioxide solid. It should be 
manganese dioxide solid. 


If you have access to a supervised laboratory, do Part A. If you do not have 
access to a supervised laboratory, do Part B. 


Part A 



Follow the instructions in the procedure on pages 46 and 47 of the textbook to 
complete both parts of the investigation. Pay special attention to the safety 
precautions mentioned. 



Although the investigation states that it is a teacher 
demonstration, your teacher may have you do the 
investigation in groups of two or three. 


Science 24 • Module 1 • Section 3 


55 


13. Answer the following on page 47 of the textbook. 

a. questions 1 , 2, and 3 of “Analyze” 

b. questions 1 to 5 of “Conclude and Apply” 




; 



Check your answers on page 1 13 of the Appendix. 


Part B 


The following are the results from a student who completed Part 1 of the 
investigation. 


Part 1 Observations: Bubbles escaped from the solution when 
manganese dioxide was added to the hydrogen peroxide. The glowing 
splint bursted into flames when it was inserted into the test tube. 


Now, complete Part 2 of the investigation as directed on page 47 of the 
textbook. Use 5 mL (1 teaspoon) of sodium bicarbonate (baking soda). If you are 
using a souvenir spoon, make sure it is actually sliver plated. 



56 


i 

1 


Science 24 • Module 1 • Section 3 


You are most likely familiar with the next type of reaction— combustion 
reactions. Whenever you burn a fuel, a combustion reaction occurs. Examples of 
combustion reactions include a wax candle burning; a match burning; logs in a 
fireplace or fire pit burning; and natural gas, propane, or fuel oil burning in your 
furnace. 


Read “Combustion Reactions” on page 48 of the textbook. Study Figure 3.7 
carefully. 

14. a. Write the word equation for the combustion of gasoline in a car. 

b. What are the reactants in this equation? 

c. What are the products in this equation? 

15. List the six materials shown in Figure 3.7 that are produced from petroleum. 

16. Read “Did You Know?” on page 48 of the textbook. Which process appears 
to be a better use of fossil fuels— using 76 L of petroleum to move a car 
485 km or using 76 L of petroleum to produce all the goods listed in the 
reading? 


( Clt^C^ Check Y° ur answers on pages 1 1 3 and 1 1 4 of the Appendix. 




Science 24 • Module 1 • Section 3 


57 


If you have ever taken an antacid to relieve an upset stomach, then you have 
felt the effects of a neutralization reaction. In this case the antacid (a base) 
neutralizes the excess stomach acid (an acid) to form a salt and water. 


Turn to pages 48 and 49 of the textbook and read “Neutralization Reactions.” 

17. a. Write the word equation for a general neutralization reaction. 

b. What are the reactants? 

c. What are the products? 

18. a. Write the word equation for the neutralization of stomach acid with 

magnesium hydroxide. 

b. One of the products is water. What is the general name for the other 
product? 

19. a. Name the substance forming the white cloud in the picture on page 49 

of the textbook. 

b. Which two substances are combining to form this compound? 



Check your answers on page 1 14 of the Appendix. 





You have now completed the concepts for this lesson. 
Do the following questions to further understand 
what you covered in this lesson. 


20. Answer questions 1 and 2 of “Check Your Understanding” on 
page 49 of the textbook. 



Go to pages 2 and 3 of Assignment Booklet 1 B and answer questions 5 to 11. 


Science 24 • Module 1 • Section 3 




Formulas for Common Compounds 


When you get together with family or friends, 
you communicate by using the same 
language. If you each use a different 
language, you will not be able to understand 
one another. Scientists from all over the 
world need to be able to communicate, even 
though they may speak different languages. 
As a result, scientists have devised a 
common language to deal with chemicals 
and chemical reactions. 

The common language scientists have 
devised is the chemical symbols and names 
for the elements and compounds. In 
previous science courses, you studied the 
symbols for some common compounds. 
Here is one such common compound. 



Water 



H 2 0 


U) 


1 . Use the symbol for water to answer the following. 

a. What is the symbol for hydrogen? 

b. What is the symbol for oxygen? 

c. How many hydrogen atoms are there in this compound? 

d. How many oxygen atoms are there in this compound? 


e. Which subscript indicates the number of oxygen atoms? 


f. What does the subscript (I) mean? 



Check your answers on page 1 15 of the Appendix. 


Science 24 • Module 1 • Section 3 


59 



chemical 
name: a 
standard 
scientific 
name by 
which each 
element or 
compound is 
known 

chemical 
formula: a 
standard 
scientific 
symbol by 
which each 
element or 
compound is 
known 


common 
name: a 
name given 
to a 

chemical 
before the 
international 
naming 
system was 
created 


Now, it’s time to get a little more background information on chemical names of 
elements and compounds and the chemical formulas that describe their 
chemical composition. 

Turn to page 50 of the textbook and read “Chemical Names and Formulas.” 

2. Where can you find a list of the names and symbols of all the chemical 
elements known to scientists? 

3. How is each symbol for a chemical element written? 

4. A chemical formula gives the of a compound. 

5. a. The word equation for the reaction of sulfur and zinc is 

sulfur + zinc — > zinc sulfide 
Write the chemical equation for this reaction. 

b. How many atoms of sulfur are present in the reactants? 

c. What rule was used to name ZnS? 

6. Read “Did You Know?” on page 50 of the textbook. Which subscript is used 
to indicate a substance dissolved in water? 




Chemicals are used by people in many 
industries. Not all these people are 
scientists. Therefore, many chemical 
compounds are often identified by 
common names. Some common names 
you may already be familiar with, like 
antifreeze for ethylene glycol, baking soda 
for sodium bicarbonate, and table salt for 
sodium chloride. 


60 


Science 24 • Module 1 • Section 3 




Read “Common Names” on page 51 of the textbook. Study Table 3.1 carefully; it 
lists the common names, chemical names, and chemical formulas of a number 
of substances. 

7. Why are common names used for many substances? 

8. Write the common name for each of the following chemical names. 

a. sodium bicarbonate b. sodium hydroxide c. methane 

9. Write the chemical formula for each of the following common chemicals, 

a. alcohol b. chalk c. quartz 

10. List the elements in each of the following chemical formulas. 

a. CaCC) . b. Si0 o , , c. KCI 

3(s) 2(s) 

Check your answers on pages 1 1 5 and 1 1 6 of the Appendix. 

If you have access to the Internet, do “Internet Connect” on page 51 of the 
textbook. You will find out more about chemical names and formulas. 




You have now completed the concepts for this lesson. 
To review what you studied, do the following questions. 



1 1 . Answer questions 1 .a. and 1 .d. of “Check Your Understanding” on page 51 
of the textbook. 




Check your answers on page 1 16 of the Appendix. 


Go to pages 3 and 4 of Assignment Booklet 1 B and answer questions 12 to 16. 


Science 24 • Module 1 • Section 3 


61 


Chemical Equations 



In Lesson 3 you studied chemical formulas. When chemical formulas are used to 
represent substances in a reaction, you get a chemical equation. Chemical 
equations are used to represent all reactions. In mathematics you work with 
equations. What you do to one side of the equation must be done to the other 
side to keep the equation balanced. Similarly, in chemical equations you need 
have the same number of atoms on each side to balance the equation. 

1 . Previously, you studied the neutralization reaction that occurs when you 
combine vinegar and baking soda. If you were able to measure the mass of 
the reactants and then the mass of products in this reaction, how do you 
think these masses would compare? 


Check your answer on page 1 16 of the Appendix. 

Experiments like the one involving vinegar and baking soda are similar to the 
experiments Antoine Lavoisier performed. Lavoisier’s experiments led to the 
development of the Law of Conservation of Mass. In a chemical reaction the 
mass of the reactants is always equal to the mass of the products. 



62 


Science 24 • Module 1 • Section 3 



Turn to page 52 of the textbook. Read introductory paragraphs of “Chemical 
Equations” and the information in “The Law of Conservation of Mass.” In “Try 
This!” the statement “Allow the gas to escape” should read, “Do not allow the 
gas to escape.” 


2. What chemical did Antoine Lavoisier start with for his experiment? 

3. What were the products of Antoine Lavoisier’s experiment? 


4. a. How is the experiment Antoine Lavoisier performed similar to the baking 
soda and vinegar experiment described in the reading? 

b. Name the law that describes the results of Antoine Lavoisier’s 
experiment. What does this law state? 



Check your answers on page 1 16 of the Appendix. 




balanced 
chemical 
equation: a 
1 reaction 
equation that 
i has the same 
number of 
! atoms of 
each element 
I! on both sides 
[! of the 
jj equation 




If you have access to an accurate balance, do the activity 
in "Try This!" on page 52 of the textbook. It sure helped me 
understand the Law of Conservation of Mass a bit better. 


Chemists use chemical equations to represent chemical reactions. These 
equations must be balanced to show the proper proportion of reactants and 
products. Balancing an equation means making sure an equation has the same 
elements and the same number of atoms of each element on both sides. 



Read “Staying Balanced” on page 53 of the textbook for further information on 

balanced chemical equations. 


5. Why do chemists use a chemical equation rather than a word equation to 
represent a reaction? 



Check your answer on page 1 16 of the Appendix. 


Science 24 • Module 1 • Section 3 


63 




6. What is a subscript? What does a subscript 
tell you? 


Some chemical equations are easy to balance, but 
some are really complex and hard to balance. You 
really have to keep track of all the elements involved. 


That's true. Let's first look at simple 
chemical equations. Read the information 
in "Math Connect: Checking the Balance 
of Simple Equations"on page 53 of the 
textbook. Pay special attention to the 
steps for checking the balance. 


7. Complete question 2 of “Solve These” on page 53 of the textbook. 



Check your answers on pages 1 1 6 and 1 1 7 of the Appendix. 



Now it's time to check more complex chemical 
equations. Read "Math Connect: Checking the 
Balance of Complex Equations"on page 54 of the 
textbook. Again, carefully follow the steps given. 


8. What is a coefficient? What does the coefficient tell you? 

9. Use the sample problem on page 54 of the textbook, 

2 H 2 0 (|) -> 0 2(g) + 2 H 2 , to answer the following. 

a. How many molecules of water are in the chemical equation? 

b. How many molecules of oxygen are on the right side of the equation? 

c. How many molecules of hydrogen are on the right side of the equation? 


Science 24 • Module 1 • Section 3 


d. How many atoms of each substance are on the left side of the equation? 


e. How many atoms of each substance are on the right side of the 
equation? 

f. Is the equation balanced? Why? 



10. Answer questions 1 , 2, and 3 of “Solve These” on page 54 of the textbook. 
State the number of atoms of each element on each side of the chemical 
equation. 



Check your answers on pages 1 1 7 to 120 of the Appendix. 




/ 



Although time-consuming, you can also use 
molecular models to check if a chemical 
equation is balanced. Check out the next activity. 


Find Hut 





Working with Chemical Compounds 

Read the entire activity on page 55 of the textbook. 

Follow the instructions in “What to Do” carefully. Use any available 
materials at home, like jujubes, to build the molecular models for each 
chemical equation in this activity. Make sure you use the same colour 
for atoms that are the same in all the molecules in the equation. For 
example, every red foam ball (or jujube) can represent an oxygen atom. 


1 1 . Answer questions 1 and 2 of “What Did You Find Out?” 


V 



Check your answers on page 121 of the Appendix. 


J 


Science 24 • Module 1 • Section 3 





65 



Example 


Is the following chemical equation 
balanced? 


I like to break down the reactants and products 
into their individual atoms when checking 
whether a chemical equation is balanced. 
Here's an example of how I check equations. 


CH + 20, n ^ CO_+ 2 H O 

4 (g) 2 (g) 2 (g) 2 (g) 


Solution 


Reactants = CH 4 + 2 0 2 

= ( C+H 4 ) + ( 0 2 + 0 2 ) 

= c+(h+h+h+h)+(o+o)+(o+o) 

= C + (H + H + H + H) + (0 + 0 + 0 + 0) 

= 1 carbon atom, 4 hydrogen atoms, 4 oxygen atoms 


Products = C0 2 + 2 H 2 O 

= (c+o 2 )+(h 2 o+h 2 o) 

= c+(o+o)+(h 2 +o)+(h 2 +0) 

= C + (0 + 0) + (H + H) + 0 + (H + H) + 0 
= C + (H + H + H + H) + (0 + 0 + 0 + 0) 

= 1 carbon atom, 4 hydrogen atoms, 4 oxygen atoms 



The equation is balanced. 


That’s a really good method of checking the 
balance of a chemical equation. It is thorough, 
and it doesn't take up as much room. Good Job! 


66 


Science 24 • Module 1 • Section 3 




You have now completed the concepts for this lesson. 
Do the following questions to review what you covered 


12. Answer questions 1 , 2, and 3 of “Check Your 
Understanding” on page 55 of the textbook. 



Check your answers on pages 121 to 123 of the Appendix. 


Go to pages 5 and 6 of Assignment Booklet 1 B and answer questions 17 to 20. 



In this section you represented 
chemical equations using words and 
chemical formulas. You identified and 
described different reactions and can 
now recognize the chemical formula 
for some common compounds. You 
also examined four different types of 
chemical reactions. You then 
discovered why scientists use 
balanced equations to represent 
chemical reactions and how the Law 
of Conservation of Mass applies to 
chemical reactions. 



One type of chemical reaction you learned was the neutralization reaction. If you 
or somebody you know has taken an antacid tablet to calm an upset stomach, 
you are already familiar with the effects of this type of reaction. 

For a review of chemical reactions, chemical formulas and equations, and 
checking if chemical equations are balanced, insert the Science. Connect 2 
Student Multimedia CD into your computer. Launch the applet “Chemical 
Reactions,” starting with Part 1 : Introduction to Chemical Equations. Answer 
questions 1 to 6 as you proceed through the applet. 


24 • Module 1 • Section 3 


67 


D 


1. Which three chemical reactions were described in the Introduction (Part 1)? 

2. List three important points of the Law of Conservation of Mass (Part 2). 

3. List five signs of a chemical reaction (Part 3). 

4. What are three ways to describe a chemical reaction as stated in Part 4? 

5. Use Part 5: Simple Decomposition Reactions to answer the following. 

a. How does the amount of hydrogen compare to the amount of oxygen 
when water is decomposed in a Hoffman apparatus? 

b. How does the amount of hydrogen compared to the amount of oxygen 
produced relate to the chemical equation for the decomposition of water? 

c. How does the diagram for the decomposition of water show that mass is 
neither lost nor created? 

6. a. How many atoms of each substance are present on each side in the 

formula in Part 6? 

b. Is the equation balanced? Explain how you know. 

7. Answer the following “Chapter 3 Review” questions on pages 56 and 57 of 
the textbook. If necessary, go back and read over parts of this section as you 
answer the questions. 

a. questions l.a., I.c., and l.d. of “Reviewing Key Terms” 

b. questions 3. a., 3.C., and 6 of “Understanding Key Ideas” 

c. questions 8. a., 8.C., and 8.f. of “Developing Skills” 

d. question 10 of “Problem Solving/Applying” 

e. question 12 of “Critical Thinking” 




68 


Science 24 • Module 1 • Section 3 




Are you aware of the problems of acid rain? Acid rain is one of the main 
concerns in the environment today. Acid rain is the product of the chemical 
reaction between water and the products of the combustion reaction of burning 
fossil fuels. Due to lower levels of industrialization, acid rain is not as much of a 
problem in western Canada today as it is in central and eastern Canada. 
However, the amount of industry in western Canada is increasing. Therefore, the 
environment needs to be monitored carefully and strict pollution controls need 
to be applied to prevent acid rain from becoming a larger problem here. 


In this section you will study how chemical reactions can affect the environment. 
You will describe changes to reactants and products in fossil fuel combustion 
reactions and investigate how the products affect the environment. You will 
explore common acid-base neutralization reactions and discover how new 
technologies can reduce the emissions that affect the environment. You will then 
describe changes to reactants and products in rusting reactions and what can 
be done to reduce corrosion. 



Turn to page 59 of the textbook and read “What You Will Learn,” “Why It Is 
Important,” and “Skills You Will Use.” These points provide a brief summary of 
what you will study in this section. 




Science 24 • Module 1 • Section 4 


69 



Fossil Fuel Combustion 



Did you shower this morning with water from a natural gas hot-water tank? Did 
you switch on a light or use an electric hair dryer? Did you ride a bus or drive a 
car today? If you answered yes to any of these questions, then you rely on the 
combustion (burning) of fossil fuels. 

In combustion reactions, fossil fuels combine rapidly with oxygen gas to form 
carbon dioxide and water vapour. This reaction also releases energy. 


! 



For a description of fossil fuel reactions and a chemical equation for the 
combustion of a particular fossil fuel, turn to page 60 of the textbook. Read the 
introductory paragraphs of “Fossil Fuel Combustion.” 


1 . Name three types of fossil fuels you are familiar with. 

2. What type of energy is given off by a combustion reaction? 

3. a. How can the energy of a combustion reaction be used in a car engine? 



b. Write the word equation for the combustion of octane. 


c. What do you notice about the chemical equation for the combustion of 
octane compared to most of the equations you have seen previously in 
this module. 



Check your answers on pages 125 and 126 of the Appendix. 


Science 24 • Module 1 • Section 4 


70 



Starting Paint 




The Halifax Explosion 

Read the entire activity on page 59 of the textbook. 

If you have access to the Internet, you may wish to visit the site given in 
“Internet Connect.” Explore this site to uncover the cause of the Halifax 
explosion. 




You can easily see evidence of a combustion reaction 
by observing a candle burning. You will look for evidence 
of a chemical reaction in the next activity. 


Evidence of a Combustion Reaction 

Read the entire activity on page 61 of the textbook. 

Carry out the instructions in “What to Do” carefully. In Part 2 make sure 
you lower the glass jar until the rim is in the coloured water. Pay special 
attention to the safety precautions mentioned. 

4. What evidence of a combustion reaction did you see in Part 1 ? 

5. What evidence of a combustion reaction did you see in Part 2? 

6. Why did the water rise up the jar in Part 2? 

ceSd Check your answers on page 126 of the Appendix. 


Science 24 • Module 1 • Section 4 


71 


The previous activity showed that combustion is incomplete when not enough 
oxygen is available. The evidence for incomplete combustion was shown when 
unburned carbon particles from the candle flame coated the inside of the jar. 

For more information on incomplete and complete combustion, read the 
information in “Incomplete Combustion” on page 61 of the textbook. 

7. What causes incomplete combustion? 

8. List the products of a complete combustion of a fossil fuel. 

9. List the products of an incomplete combustion of a fossil fuel. 

10. What is carbon monoxide? Why is it dangerous? 

1 1 . Where do you see the carbon from incomplete combustion in a fireplace? 



Check your answers on page 126 of the Appendix. 



Global climate change is a topic of interest to scientists 
and others. Although climate change has occurred 
throughout history, studies are showing that climate 
change is occurring at a much faster rate in the past 
century. 


Earth’s temperature and precipitation is maintained at a 
fairly constant rate by greenhouse gases. Turn to page 62 
of the textbook and read “Greenhouse Gases.” You will read about the 
importance of greenhouse gases and global climate change. 


12. Which gases are produced by all living things? Are these gases produced by 
industry and general human activities? 

13. What global average temperature do greenhouse gases maintain? 

14. Why are scientists concerned about climate change? 

15. What activities on Earth might be contributing to global climate change? 



Check your answers on pages 126 and 127 of the Appendix. 


Science 24 • fVlodule 1 • Section 4 





4-A: Climate Change: What Is Your Position? 


Read the entire investigation on page 63 of the textbook. 


If you have access to the Internet, use 
any of the Internet’s search engines to 
find information on global climate 
change. You can most likely obtain 
access to the Internet at your local 
library. Also, use library books to search 
for information on global climate change. 
Try to find information that is current (at 
least 1995 or later). 


It is not necessary to work in groups to 
complete this research. If you are 
working alone, find information that both 
supports and refutes the scientific 
viewpoint that human activities are 
directly related to climate change. 


16. State, in point form, the information 
you have found that supports the 
scientific viewpoint. 


17. State, in point form, the information you have found that refutes the 
scientific viewpoint. 

18. Write a short report stating your opinion on the two positions. 

Check your answers on pages 127 and 128 of the Appendix. 




Science 24 • Module 1 • Section 4 


73 


pollutant: a 
released 
chemical 
that harms 
living things 
and the 
environment 




acid 

deposition: 

acid 

material, 
both solid 
and liquid, 
deposited on 
Earth 


Carbon dioxide, water vapour, and methane are 
not the only substances released into the 
atmosphere by human activities. Other chemicals 
that cause harm to living things are also released 
into the environment. These chemicals are called 
pollutants. 

To learn about other pollutants and their effects, 
turn to pages 64 and 65 of the textbook. Read 
“Air Pollution,” and study Figures 4.3A and 4.3B 
carefully. 

19. a. Name two pollutants released into the 

atmosphere by natural and human 
activities. 

b. What are the sources of these pollutants 
that are released into the atmosphere? 

c. What substances are products of a reaction between these substances 
and water in the atmosphere? 

20. What does the subscript (aq) mean? 

21 . What is the more accurate term for acid precipitation? 



Check your answers on page 128 of the Appendix. 

Insert the Science. Connect 2 Student Multimedia CD into your computer. 
Launch the “Acid Deposition” applet, starting with Part 1 : Introduction to Acid 
Deposition. Work your way through the entire applet, and answer the following 
questions. 

22. Name three things affected by acid deposition. 

23. a. What is the pH range for acids? 

b. Which is more acidic— normal rainwater or lemon juice? Explain. 

24. Explain how the demonstration in Part 3 showed you that vehicle exhaust 
helps form an acid. 




74 


Science 24 • Module 1 • Section 4 


25. a. Which two elements form nitrogen monoxide? 

b. Where is the nitrogen monoxide formed in a vehicle engine? 

c. What component in addition to nitrogen and oxygen is required to form 
nitrogen monoxide? 

26. Which two gases form nitrogen dioxide? 

27. Which two substances combine to form nitric acid? 

28. a. In which step(s) is nitrogen monoxide a reactant? 


b. In which step(s) is nitrogen monoxide a product? 

29. Name the reactants and products of a fuel cell. 


30. Which acid results from sulfur dioxide gas produced by the combustion of 
coal? 

31 . What is the purpose of a scrubber in a smokestack of a coal-burning plant? 


32. Write a summary of how acid deposition results from nitrogen dioxide 
produced by volcanoes, burning forests, industry, and motor vehicles. 

Check your answers on pages 128 and 129 of the Appendix. 



You have now completed the concepts for this lesson. 
Do the following questions to review what you studied 

33. Answer questions 2 and 4 of “Check Your 
Understanding” on page 65 of the textbook. 





Check your answers on page 129 of the Appendix. 


Go to pages 7 and 8 of Assignment Booklet 1 B and answer questions 1 to 6. 


Science 24 • Module 1 • Section 4 


75 


Acid-Base Reactions 


Many people, some more than others, are 
familiar with the relief antacid tablets 
provide. Whether it is from eating spicy 
foods or just eating too much, people 
have turned to antacids for relief of 
heartburn and upset stomach. The 
reaction between the antacid tablet(s) 
and excess stomach acid, which causes 
heartburn and upset stomach, results in 
the neutralization of the excess stomach 
acid. This is one example of the many 
acid-base reactions known to people 
throughout the world. 

The neutralization of stomach acid with 
sodium bicarbonate is a natural process 
that occurs in the small intestine. To learn 
more about this neutralization reaction, 
read the introduction to “Acid-Base 
Reactions” on page 66 of the textbook. Examine Figure 4.4 closely. 

1 . Where does the hydrochloric acid present in digestion come from? 

2. Why does the stomach not digest itself? 

3. Which organ produces sodium bicarbonate? 

4. What happens to acidic food in the small intestine? 

5. Write the word and formula equations for the neutralization of stomach acid 
with sodium bicarbonate. 


Check your answers on page 129 of the Appendix. 




Science 24 • Module 1 • Section 4 




Read “Acids and Bases in the Environment” on pages 66 and 67 of the 
textbook. 

6. a. What is liming? 

b. What is the purpose of liming? 

c. Why is liming not a permanent solution to acidity in a lake? 


7. Use the pH scale at the top of page 67 of the textbook to determine the 
change in pH when acidic lake water is neutralized with calcium carbonate. 


8. Write the word and formula equations for the neutralization of acid lake water 
with calcium carbonate. 




Check your answers on page 130 of the Appendix. 



If you have access to universal pH indicator paper, 
do'Try This!" on page 67 of the textbook. 


Liming is not a permanent solution to reducing the acidity in lake water because 
continued acid deposition increases acidity in lake water. Acid deposition is 
caused by sulfur and nitrogen oxides present in the atmosphere. To reduce acid 
deposition, you must reduce the sulfur and nitrogen oxides. 

f 

\ Science 24 • Module 1 • Section 4 



77 


You may have seen large, yellow piles in various 
places in Alberta. These piles are sulfur that has 
been removed from fossil fuels like natural gas. 
Read “Reducing Emissions,” “Removing Sulfur 
from Fuel,” and “Sulfur Scrubbing” on pages 67 
and 68 of the textbook. You are given more 
information on how sulfur can be removed from 
combustion fuels. 

9. Name one plant location where sulfur is 
removed from natural gas. 

10. Why is coal mined in Alberta valued? 

1 1 . a. What process is used to remove sulfur 

from the burning of coal? 



b. Explain the process involved in removing sulfur from the burning of coal. 


12. How effective is sulfur scrubbing? 



Check your answers on page 130 of the Appendix. 




You have now completed the concepts for this lesson. 
Do the following questions to review what you studied 


13. Answer questions 2 and 3 “Check Your Understanding” on page 68 of the 
textbook. 



Go to pages 8 and 9 of Assignment Booklet 1 B and answer questions 7 to 1 1 . 


Science 24 • Module 1 • Section 4 



Corrosion of Iron 



The vehicle in the photograph is showing signs of corrosion (rusting). The iron 
and steel in the body of this truck is turning to a red-brown colour and pieces of 
the metal are flaking off. 




4-B: Corrosion of Iron 

Turn to pages 70 and 71 of the textbook and read the entire investigation. 
1 . Answer the question posed in “Prediction” on page 70. 



Check your answer on page 131 of the Appendix. 


Science 24 • Module 1 • Section 4 


79 


If you have access to a supervised laboratory or if you can obtain the required 
equipment, do Part A. If you do not have access to a supervised laboratory, do 

Part B. 


Part A 


Obtain the required materials and follow the procedure to complete the 
investigation. Use steel wool that is used for furniture refinishing rather than 
steel wool soap pads. You may add some food colouring to the water to make it 
easier to see the water level in the test tubes and graduated cylinders. 

Pay special attention to the safety precautions mentioned. 

2. Answer the following on page 71 of the textbook. 

a. questions 1 , 2, and 3 of “Analyze” 

b. questions 4 and 6 of “Conclude and Apply” 


eSc 


Check your answers on page 131 of the Appendix. 


Part B 

You will observe a demonstration of the corrosion of iron in this investigation. 
Insert the Science 24 Multimedia CD into your computer, and view the segment 
“Corrosion of Iron.” 

3. Complete the following table as you view the segment. Just indicate where 
the water is relative to the bottom of the test tube in the graduated cylinder. 


start 



Water Level 

Tc 

N 

*st Tube with 
o Steel Wool 

Test Tube with Test Tube with 

Wet Steel Wool Dry Steel Wool 






after 24 hours 


4. Answer the following on page 71 of the textbook. 

a. questions 1 , 2, and 3 of “Analyze” 

b. questions 4 and 6 of “Conclude and Apply” 




Turn to page 69 of the textbook for more information on rusting. Read the 
introduction to “Corrosion of Iron.” 


5. Define the term corrosion. 

6. Why is the corrosion of steel and iron a 
serious problem? 

7. a. Write out the equation for the rusting 

of iron. 

b. What are the reactants? 

c. What product is formed? 



d. What additional substance, not shown in the equation, is required for 
rusting? 


8. What type of reaction is the rusting of iron? How do you know? 

9. What is one metal that does not corrode? 

10. Answer question 3 of “Check Your Understanding” on page 71 of the 
textbook. 




Ch^IC ^ eck y° ur answers on P a 9 e “132 of the Appendix. 

io to *3 Go to page 9 of Assignment Booklet 1 B and answer questions 12 to 15. 


Science 24 • Module 1 • Section 4 




81 


Solving the Problem of Corrosion 


Has anyone you know had his or her vehicle, 
wagon, or metal chairs repainted? What is 
the purpose of painting certain metals? 

How does painting prevent corrosion? 



In Lesson 3 you discovered that corrosion 
is a serious problem for society because 
iron and steel are used for many things. Turn 
to pages 72 and 73 of the textbook. Read 
“Solving the Problem of Corrosion” to 
learn about ways of preventing 
corrosion. ^ 


1 . How does painting reduce corrosion? 

2. Why does painted iron or steel rust anyway after a period of time? 

3. a. What is galvanization? 

b. How does galvanization prevent corrosion? 

c. Why is galvanization better than painting? 

4. a. What is a sacrificial metal? 

b. Which metals are commonly used as sacrificial metals? 

5. What is the equation for the corrosion of magnesium? 


Check your answers on pages 132 and 133 of the Appendix. 



Science 24 • Module 1 • Section 4 




You may wish to use the Internet to learn more about corrosion and corrosion 
prevention. Enter various key words, like bridge corrosion, pipeline corrosion, 
and metal rusting into any of the Internet’s search engines. Explore various sites 
and topics relating to corrosion. 




You have now completed the concepts for this lesson. 
Do the following question to further your understanding. 



6. Answer question 2 of “Check Your Understanding” on page 73 of the 
textbook. 



ChIC^ Check your answer on page 133 of the Appendix. 

Go to page 10 of Assignment Booklet IB and answer questions 16 to 18. 


Science 24 • Module 1 


Section 4 


83 



In this section you described changes to 
reactants and products in fossil fuel 
combustion reactions and investigated 
how the products affect the 
environment. You explored common 
acid-base neutralization reactions and 
discovered how technologies can 
reduce the emissions that affect the 
environment. You then described 
changes to reactants and products in 
rusting reactions and what things can be 
done to reduce corrosion. 

You now know that chemistry plays an 
important part in producing the 
products and conveniences you enjoy 
today. You also know that producing 
some of these products and 
conveniences have a negative affect on 
the environment. Knowing more about 
chemical reactions will help you make 
choices that are good for you and for 
the environment. 




You have now covered all of the concepts for this section. To further your 
knowledge, answer the following “Chapter 4 Review” questions on pages 74 
and 75 of the textbook. If necessary, go back and read over part of this section 
as you answer the questions. 


1. Answer question 1 of “Reviewing Key Terms.” 

2. Answer questions 3, 4, 5, 6, and 8 of “Understanding Key Ideas.” 

3. Answer question 1 1 of “Developing Skills.” 

4. Answer question 13 of “Problem Solving/Applying.” 



Check your answers on pages 133 to 135 of the Appendix. 




84 


Science 24 • Module 1 • Section 4 



In this module you investigated chemical change that occurs in every part of 
your daily life. 


In Section 1 you studied how chemistry is useful in everyday life and learned 
about common chemical reactions. You discovered that everyday life has 
changed a lot in the past 100 years due to people’s growing knowledge of 
chemistry. 

In Section 2 you studied several different types of chemical reactions and 
discovered how some chemical reactions can be useful to you. You described 
different types of chemical reactions and identified evidence of some chemical 
reactions. 


In Section 3 you learned how to write word 
equations for some chemical reactions. 

You learned why chemists use balanced 
equations and how the Law of 
Conservation of Mass applies to 
chemical reactions. 


In Section 4 you explored chemical 
reactions that can affect the environment 
and identified problems that these 
reactions may cause. You described how 
some technologies can reduce emission 
that affect the environment. 

You performed a number of activities and 
investigations relating to evidence of 
chemical reactions and energy resulting 
from or used by chemical reactions. You 
learned that knowing more about 
chemical reactions and making wise 
choices about some of the conveniences 
you have enjoyed can be good for the 
environment. 


equations and chemical formula 



Science 24 • Module 1 • Section 4 


85 


: 



■I 


APPENDIX- 


GLOSSARY ■ SUGGESTED ANSWERS ■ IMAGE CREDIT 


CHANGE ■ MDDULE I ■ MATTER AND CHEMICAL CHANGE - MODULE I » ND CHEMICAL CHANGE 


Glossary 

acid deposition: acidic material, both solid 
and liquid, deposited on Earth 

acid precipitation: rain, snow, fog, or dew 
that is acidic 

alloy: a mixture of two or more metals; looks 
like one metal 

balanced chemical equation: a reaction 
equation that has the same number of 
atoms of each element on both sides of 
the equation 

chemical name: a standard scientific name 
by which each element or compound is 
known 

chemical formula: a standard scientific 
symbol by which each element or 
compound is known 

chemical reaction: a transformation that 
occurs when substances react, forming 
one or more new substances with 
properties different from the original 
substances 

climate change: the natural process of 
warming and cooling intervals over 
Earth’s history 

coefficient: a number written in front of a 
chemical formula to balance a chemical 
equation 

common name: a name given to a chemical 
before the international naming system 
was created 


corrosion: a process that chemically breaks 
down or degrades metal 

endothermic reaction: a chemical reaction 
in which thermal energy (heat) is 
absorbed 

exothermic reaction: a chemical reaction in 
which thermal energy (heat) is released 

galvanization: a process used to protect 
iron or steel from rusting by applying a 
zinc coating 

greenhouse gas: a gas that traps heat in 
Earth’s atmosphere 

e.g., carbon dioxide, methane, and water 
vapour 

herbicide: a chemical used to kill unwanted 
plants 

insecticide: a chemical used to kill insects 

liming: a technique in which lime is added to 
acidic lake water to raise the pH 

nitrous oxide: a gas produced from natural 
and industrial sources that forms acid 
precipitation when mixed with water 
vapour in the atmosphere 

pollutant: a released chemical that harms 
living things and the environment 

product: a substance present after a 
chemical reaction 

reactant: a substance present before a 
chemical reaction 


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Science 24 • Module 1 • Appendix 


rusting: the corroding of iron or steel 

sacrificial metal: a metal attached to a 
metal object that corrodes instead of the 
metal object 

For example, magnesium is attached to a 
pipeline or a ship’s hull to keep the 
pipeline or ship’s hull from corroding. 

scrubber: a device installed in the 

smokestacks of coal-burning industrial 
plants to remove sulfurous emissions 

simple composition reaction: a reaction in 
which two or more elements combine to 
form a compound 

This type of reaction usually involves the 
release of energy. 


simple decomposition reaction: a reaction 
in which a compound is broken down into 
its elements 

This type of reaction requires energy to 
drive the reaction. 

sulfur dioxide: a gas released from natural 
or industrial combustion that forms acid 
precipitation when mixed with water 
vapour in the atmosphere 

synthetic: human-made 

synthetic polymer: any one of a number of 
long-chain compounds made in a 
laboratory 

word equation: a convenient method of 
using words to describe what happens in 
a chemical reaction 


Suggested Answers 

Section 1: Lesson 1 

1. Farming 150 years ago consisted of animal and manual labour to plant, grow, and 
maintain crops, gardens, and livestock. The technological advances farmers use today 
include automatic feeders, barn cleaners, and modern tractors with tillage equipment to 
do the work. 

2. Farmers 150 years ago pulled weeds in fields and picked insects off crops in gardens. The 
chemical advances that have changed farming today are the use of chemical pesticides to 
kill unwanted plants and insects and the use of fertilizers to produce larger crop yields. 

3. Chemical and technological advances have provided 

• increased food production 

• more appealing fruit and vegetables 

• food with a longer shelf life 


Science 24 • Module 1 • Appendix 


89 


4. Manufactured fertilizers are more effective than natural fertilizers because they are 
designed for specific crops and soil conditions. 

5. Natural fertilizers provide organic matter to the soil. 

6. A pesticide like Dursban must be handled with care because it can damage the brain and 
central nervous system if inhaled or ingested. 

7. Farmers can learn about the precautions required when handling pesticides by carefully 
reading the labels on the product and any literature that accompanies the product. 

8. Over the past 100 years soaps have been improved by adding ingredients that make 
them smell nice, produce more suds, and help soften skin. 

9. Soap consists of two-ended molecules that allow one end to dissolve in grease while the 
other end dissolves in water. This allows water to wash away any grease. 

10. The soap feels similar to soaps of today; it is slippery and produces lather. It does not, 
however, lather as well as today’s soaps. Also, the soap does not have a nice fragrance; 
but, then again, no fragrances were added. 

1 1 . Answers will vary. Although soap making is a large commercial industry with dozens of 
brands on the market, soap making is also a popular, home-based business. At one time, 
various types of animal fat were used to make soap. Today, many varieties of ingredients 
are used: goats milk, glycerine, coconut oil, vegetable oils, and oatmeal to name a few. 
Various natural fragrances are used to scent the soaps. Soap making 100 years ago 
often used stove ashes as the base in place of lye (caustic soda). Today, you can buy 
ready-made bases, where you only need to melt and add softening or fragrance 
ingredients. 

12. Sports items made from synthetic materials include 

• hockey jerseys (polyesters) 

• canoes (Kevlar) 

• tents (nylon) 

• netting for basketball hoops (nylon) 

• waterproof and wind proof jackets (Gore-Tex) 

13. Polyester is a good material for sports clothing because it does not absorb moisture and 
it retains its shape. 


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Science 24 • Module 1 • Appendix 


14. Nylon was first made from coal, water, and air. 


Note: Today, nylon is made from a substance called caprolactam, which 
is made from several products produced by the petrochemical industry 





15. Textbook question “Try This!,” p. 8 

The synthetic and natural fibres are the same in that they are made of a single strand. The 

fibres differ in that synthetic fibres are smoother than natural fibres. 

16. Textbook questions 1, 2, and 3 of “Check Your Understanding,” p. 9 

1 . Chemicals have made modern farming easier by destroying weeds and insects that 
farmers would have to destroy by hand. Chemicals in fertilizers make farming easier by 
providing nutrients required by the crop rather than farmers having to haul and spread 
natural fertilizer (manure). 

2. The process of making soap has changed in that modern methods use various plant 
oils instead of animal fat. Also, ingredients are added to soaps today to make more 
suds and to make them smell nicer. 

3. Synthetic fibres include polyester, nylon, Kevlar, and Gore-Tex. Natural fibres include 
cotton, linen, silk, and wool. 

Advantages of synthetic fibres are as follows: 


Section 1: Lesson 2 

1 . A polymer is a long-chain molecule made up of many small, identical sub-molecules. 

2. Most synthetic polymers are commonly known as types of plastics. 

3. Neoprene, polyethylene, polystyrene, and polyurethane are types of synthetic polymers. 

4. Lenses for eyeglasses made from a polymer are lighter and thinner than those made from 
glass. 


• Synthetic fibres have more strength. 

• Synthetic fibres do not absorb much moisture. (This may also be a disadvantage.) 

• Waterproof and windproof clothing can be made with synthetic fibres. 


Science 24 • Module 1 • Appendix 


91 


5. Textbook questions l.b., I.c., 2, and 3 of “What Did You Find Out?,” p. 10 

1 . b. The putty does not bounce, it just reshapes itself if thrown hard. The putty will 

stretch for some distance before breaking. 

c. You can roll the putty into long thin ropes, or you can flatten it into disks. 

2. Two of the original substances were liquids and the third was a semi-liquid. The new 
substance is a solid with elastic properties. 

3. The product could be used as weather stripping or as a removable bonding material. 

6. Stainless steel is used to make kitchen utensils. Stainless steel is made up of iron, 
chromium, nickel, and carbon. 

7. a. Superplastic steel is a type of steel that contains a high carbon content. 

(Ultrahigh-carbon steel contains 1 .25% to 2.00% carbon). 

b. Superplastic steel can be stretched to 100 times its length without breaking. 

c. Superplastic steel can be used to make strong, lightweight car and aircraft bodies. 

8. a. Gold, silver, and copper make up yellow 14K gold. (Other colours of gold jewellery, 

such as white gold and green gold, contain nickel or zinc). 

b. Pure gold is not used for jewellery because it is soft and would damage easily. Also, 
jewellery made from pure gold would be very expensive. 

9. Textbook question “Try This!,” p. 11 

The iron showed signs of corrosion. Stainless steel does not corrode easily and will 
maintain an easy-to-clean surface for many years. 

10. a. Brass is made up of copper and zinc. 

b. Brass is often used to make musical instruments, like trumpets and cymbals. 
(Cymbals are often made from brass alloys that include tin.) 


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Science 24 • Module 1 • Appendix 


1 1 . Textbook questions 2 and 3 of “Check Your Understanding,” p. 1 1 

2. a. Materials like polar fleece and fibrefill for lining and insulation and materials like 

nylon and Gore-Tex for windproofing and waterproofing keep you warm today. 

b. You would have used materials like wool, animal furs, and down (feathers) to keep 
you warm 1 00 years ago. 

3. Synthetic polymers include neoprene, polyethylene, polystyrene, and polyurethane. 
These materials have changed daily life by providing strong, lightweight, insulating 
materials for many everyday products, such as soles of shoes, hoses, wet suits, milk 
jugs, Styrofoam cups, insulation, upholstery, and clothing. 


Section 1 : Lesson 3 

1 . All-purpose cleaners, bleaches, toilet-bowl cleaners, oven cleaners, and drain cleaners 
are types of cleaning products used in the home 

2. Sodium hydroxide is often present in drain cleaners. 

3. Drain cleaners clear clogged drains by breaking down proteins, such as hair and skin 
cells as well as animal fats. The process creates heat, which helps to melt the grease. All 
this is then washed down the drain with water. 

4. The chemical used to clean a clogged steam iron is muriatic acid. Hydrochloric acid is 
commonly known as muriatic acid. Muriatic acid reacts with the lime buildup to form a 
soluble solution that is then rinsed away. 

5. Acetone dissolves nail polish so it can be wiped away with a paper towel or cloth. 

6. The product shows that the contents are poisonous and flammable. It also shows that the 
container is explosive. 



8. Lemon juice and mineral oil can be used to make furniture polish. 

9. The foaming action of hydrogen peroxide in a cut helps remove small particles that may 
cause infection. 


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93 


10. Bakers need some knowledge of chemistry so they know what substances and reactions 
are responsible for certain actions, like bread rising and sponge toffee having bubbles. 

1 1 . Yeast is responsible for making bread rise. 

12. Carbon dioxide formed from the reaction of vinegar and baking soda makes the bubbles 
in sponge toffee. 

13. The acids in citrus fruits and rhubarb react with utensils made of aluminum. Hydrogen 
gas forms, which corrodes the utensils. 

14. Textbook question “Try This!” p. 13 

Bubbles formed in the mixture. 

15. Some of the ingredients changed physically and blended into the mixture. After baking, 
the mixture hardened. The chocolate chips, however, remained as they were originally; 
they were visible in the mixture and in the finished product. 

16. This activity shows that you can use the chemistry terminology and measurements to 
bake chocolate chip cookies. 

17. Textbook questions 2 and 3 of “Check Your Understanding,” p. 15 

2. Chemicals commonly found in household cleaners are 

• sodium hydroxide— cleans by breaking down proteins and animal fats that clog a 
drain pipe 

• muriatic acid— cleans by reacting with lime to form a soluble product 

• acetone— dissolves a substance like nail polish so it can be wiped away 

• methanol— dissolves paint so it can be wiped or washed off a brush 

3. a. Yeast converts sugar and starch into carbon dioxide and alcohol. The carbon 

dioxide forms bubbles in the bread dough and makes it rise. 

b. You would use less yeast for flatbread because you do not want the dough to rise 
as much. 


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Science 24 • Module 1 • Appendix 


Section 1 : Lesson 4 


1 . Automotive repair shops, hair salons, offices, and construction sites are four areas of work 
where a working knowledge of chemistry is needed. 

2. Chemicals in paints, fillers, and cleaners are used in an automotive repair shop to fix and 
paint damaged car bodies. 

3. In a hair salon chemicals are used in colourants, curling solutions, shampoos, and 
conditioners. 

4. Before 1938, hair stylists removed soap scum from hair by rinsing it with an acid solution 
made up of vinegar or lemon juice. 

5. Shampoos add texture to your hair by coating each hair strand with plastic resins. 

6. Detergents have a pH of about 10.5, according to the pH scale on page 16 of the 
textbook. 

7. The manipulated variable is the brand of dish detergent. The responding variable is how 
clean the plastic glass gets. 

8. The amount of dish detergent used for each washing and the temperature of the wash 
water are variables that must be controlled. 

9. Lab reports will vary. A sample lab report is given. 

Title: Which Dish Detergent Is Best? 

Problems: Determine which dish detergent removes grease best from a plastic glass. 

Materials and Apparatus: 

• 4 different brands of dish detergents 

• 4 clear, plastic glasses 

• 4 mL of spaghetti sauce (or other source of grease) 

• 4 large beakers (or plastic basin or kitchen sink) 

Procedure: 

step 1: Obtain the required materials and apparatus. Label the detergents A to D 

(depending on how many you have). List the criteria you will use to evaluate the 
detergents. 


Science 24 • Module 1 • Appendix 


95 


step 2: Fill a beaker with warm water, or put warm water in a basin or the kitchen sink. 

step 3: Add 2 drops dish detergent A to the beaker and stir. 

step 4: Put 1 ml_ of spaghetti sauce or other grease on a clean glass. Rub the grease 
onto the glass. 

step 5: Put the glass into the beaker with the water and dish detergent. Move the glass 
around in the water for about 30 s. 

step 6: Remove the glass from the beakers, and observe how clean it looks. Record your 
observations. 

step 7: Repeat steps 2 to 6 for detergents B, C, and D. Try to have the temperature of 
the water the same for each trial. 

Observations: 


Observation 


] 


A 

glass showed signs of grease as well as some red colouring from the 
tomato sauce 

B 

glass showed some sign of grease but less than for Detergent A 

C 

glass showed no sign of grease or red colouring from the tomato sauce 

D 

glass showed a slight amount of grease 


Conclusion: In this experiment, detergent C cleaned the best. The glass showed no sign 
of grease. Detergent A cleaned the poorest. There was some appearance of grease on 
the glass; it felt a bit slippery (greasy) in this area. The other detergents were somewhere 
between in cleaning ability. Some detergents clean a plastic glass better than others. 

10. Textbook questions 1 to 4 of “Evaluate,” p. 17 

1 . Answers will vary. You may have found some dish detergents were better at removing 
grease than others. 

2. You should have found that the criteria helped you rank the detergents. 


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Science 24 • Module 1 • Appendix 


3. Detergent C cleaned the best. There was no visible evidence of grease after washing, 
and the glass did not feel greasy. 

4. Dish detergents include an active ingredient to dissolve grease and keep it suspended 
in the water so it doesn’t attach to the other dishes being washed in the same water. 

1 1 . Some cosmetics have been around for thousands of years. 

12. Knowledge of chemistry helps manufacturers control chemical reactions so cosmetics do 
what they are supposed to without hurting users. 

13. You can learn about the safety precautions required for handling a product you have not 
seen or used before by carefully reading the label. 

, 14. Workplace Hazardous Materials Information System 

15. You will find information on how the product should be stored, handled, and disposed of 
on the label of a hazardous product. 

16. Ordinary table salt can be a hazardous substance when it is handled in bulk (unpackaged) 
because dust from the salt can irritate your lungs. Also, disposal of large quantities of salt 
would require that it be treated as a hazardous product. 

17. The corrosive symbol would be on a container of a strong acid. 

18. Textbook questions 1 and 2 of “Check Your Understanding,” p. 19 

1 . Answers will vary. A sample answer is given. 

automotive repair shop: oil, gasoline, grease, fuel additives, antifreeze, window 
washer fluid 

beauty salon: hair spray, styling gel, hair colouring, hair bleaching, nail polish 

2. Answers will vary. Workers at a restaurant should understand the WHMIS labels 
because 

• corrosive cleaners are present 

• flammable materials are present and workers should know what to do in case of 
a fire 

• food additives are present and workers should know any safety issues regarding 
these additives 


Science 24 • Module 1 • Appendix 


97 


Section 1 Review 


1 . Textbook questions 3 and 5 of “Reviewing Key Terms,” p. 20 

3. Both substances are waterproof. The substances are different in that Gore-Tex is a 
synthetic fibre and cotton is a natural fibre. 

5. Answers will vary. Here are a few examples of alloys: 

• stainless steel — made from iron, chromium, nickel, and carbon 

• 14K gold alloy— made from gold and silver 

• brass— made from mostly copper and zinc (also may contain small amounts of 
aluminum, lead, tin, or nickel) 

2. Textbook question 10 of “Understanding Key Ideas,” p. 20 

10. Synthetic fabrics benefit your daily life by providing you with clothes that wear well 
and look good. They also provide you with various products made of plastic that are 
light and durable. 

3. Textbook question 15 of “Developing Skills,” p. 21 

15. You should use safety goggles, rubber gloves, and an apron when handling a 
corrosive substance. 

4. Textbook question 19 of “Critical Thinking,” p. 21 

19. The major advantage of using polymers and alloys is that the weight of the car is 
greatly reduced, which helps in reducing fuel consumption. 


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Science 24 • Module 1 


Appendix 


Section 2: Lesson 1 


1. During a chemical reaction, substances react to produce new substances with different 
properties from the original substances. 

2. The reactants are hydrogen and oxygen. The products are water and energy. 

3. The reactants are magnesium hydroxide and hydrochloric acid (stomach acid). The 
products are magnesium chloride and water. 

Note: Some antacids contain calcium hydroxide instead of magnesium 
hydroxide. The products would then be calcium chloride and water. 

j 

4. You know that a chemical reaction has occurred when bananas ripen because the skin 
turns from green to yellow to brown. 

; 5. Bananas release a ripening gas called ethylene, which triggers enzyme production. This, 
in turn, triggers colour change and softens the bananas. 

6. Hydrogen peroxide or sodium hypochlorite are the active whitening ingredients in bleach. 

7. Oxygen is the common element present in these whitening ingredients. 

8. To make bread, flour is mixed with yeast and water. The enzymes in the yeast break 
down the starch in the flour into glucose. Other enzymes react with the glucose to 
produce ethanol (an alcohol) and carbon dioxide. The carbon dioxide bubbles through the 
dough mixture, causing the dough to rise. When the dough is placed in the oven, the heat 
helps the carbon dioxide bubbles expand and make the bread light and airy. 

9. The alcohol released into the dough burns off, leaving a delicious flavour. 

10. Digestion begins in the mouth, where an enzyme called amylase breaks down starches 
into simple sugars. In the stomach, an enzyme called protease speeds up the breakdown 
of proteins into amino acids. Next, partially digested food goes into the small intestine. 
Here an enzyme called lipase breaks down fats into glycerol and fatty acids. 

1 1 . Hypochlorous acid is produced when chlorine is added to water. 

12. People should wear rubber gloves and eye protection when using chlorine. 

13. These containers usually contain the “corrosive contents” symbol. 


Science 24 • Module 1 • Appendix 




99 


14. Answers will vary. Your predictions for each part should be similar to the following: 

Part 1: The limewater will turn milky if carbon dioxide is present. 

Part 2: If hydrogen is present, there will be a “pop” or “squeal” when the burning splint is 
inserted into the test tube. 

Part 3: If oxygen is present, the glowing splint will burst into flames when inserted into 
the test tube. 

15. a. Textbook questions 1 and 2 of “Analyze,” p. 27 


1 


carbon dioxide (C0 2 ) 

The limewater turned milky. 

hydrogen (H 2 ) 

There was a “pop” when the burning wooden 
splint was inserted into the test tube. 

oxygen (0 2 ) 

The glowing splint burst into flames when inserted 
into the test tube. 


2. The results of the three tests confirmed the predictions, 
b. Textbook question 3 of “Conclude and Apply,” p. 27 

3. Answers will vary. Some problems that may occur are as follows: 

• Not enough gas was produced by the reaction. 

• Some gas was lost when the test tube was turned over. 

16. A black coating and drops of water appear on the inside of the beaker (or glass). The 
black coating is formed when unburned carbon contacts and sticks to the glass. The 
drops of water are formed when water vapour produced by the combustion condenses 
on the cold glass. The reactants are candle wax (carbon and hydrogen) and oxygen (from 
the air). The products are water vapour, carbon dioxide, and carbon (from incomplete 
combustion). 


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Science 24 • Module 1 • Appendix 


17. Textbook questions 1, 3, and 4 of “Check Your Understanding,” p. 28 

1 . Chemical reactions mentioned in this section were as follows: 

• Hydrogen and oxygen combine to produce water and energy. 

• Enzymes and glucose combine to form carbon dioxide and ethanol. 

• Water and chlorine combine to produce hypochlorous acid. 

• Vinegar and baking soda combine to form carbon dioxide and other products. 

• Hydrogen peroxide and dry yeast combine to form hydrogen gas and other 
products. 

• Hydrogen peroxide and maganese dioxide combine to form oxygen gas and 
other products. 

3. Chlorine or oxygen gas might be formed. 

4. Bleach containers are not transparent so sunlight cannot pass through the container 
and affect the bleach. 

Section 2: Lesson 2 

1 . Textbook questions 1 and 2 of “What Did You Discover?,” p. 23 

1 . An increase in the temperature (flask got warmer), the inflation of the balloon, and a 
colour change are evidence of a chemical change. 

2. The increase in temperature showed that energy was released. 

2. You know that energy was released because the temperature of the solution increased. 

3. The balloon inflated in step 3. This is evidence that a chemical change has occurred. 

4. The substances present before a reaction are called the reactants. 

5. The substances present after a reaction are called the products. 


Science 24 • Module 1 • Appendix 


101 


6. The three main indicators that a chemical reaction has occurred are as follows: 

• Gases are given off. 

• New solids are formed. 

• The colour changes. 

7. Yes, an odour may be given off in some chemical reactions. 

8. The building collapsing is evidence that a reaction has occurred. 

9. A chemical reaction in which a fuel is burned in the presence of oxygen is called a 
combustion reaction. 

10. The products of a burning candle in the presence of oxygen are carbon dioxide and 
water. 

1 1 . Chemical reactions involving an acid added to a base to produce a new compound and 
water are called neutralization reactions. 

12. Cooking often involves acid-base reactions. 

13. a. Magnesium hydroxide is the base commonly found in antacid medication. 

b. magnesium hydroxide + hydrochloric acid -» magnesium chloride + water 

c. Magnesium chloride and water are formed. 

14. Answers will vary. The ingredients in your toothpaste will most likely match many of the 
ingredients listed in the “Did You Know?” section. 

15. Textbook questions 1, 2, and 3 of “What Did You Find Out?,” p. 30 

1 . Baking soda and vinegar were mixed when you did the test for carbon dioxide gas in 
Investigation 2-A. Carbon dioxide gas is produced when you mix baking soda with 
vinegar. 

2. The candle flame went out. 

3. The candle flame went out because carbon dioxide is heavier than air and sinks over 
the flame, displacing the oxygen around the flame. Without oxygen, the combustion 
cannot continue. 


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Science 24 • Module 1 • Appendix 


16. Textbook questions 1, 2, and 3 of “Check Your Understanding,” p. 30 

1 . Some combustion reactions are as follows: 

• natural gas burning in a furnace: The reactants are natural gas and oxygen. 

The products are carbon dioxide, water, and energy. 

• gasoline or diesel burning in an engine: The reactants are octane and oxygen. 
The products are carbon dioxide and water vapour. 

• a candle burning: The reactants are candle wax and oxygen. The products are 
carbon dioxide, water, and energy. 

• a lit lighter: The reactants are butane and oxygen. The products are carbon 
dioxide and water vapour. 

2. Answers will vary. One neutralization reaction that occurs in the kitchen is vinegar (or 
lemon juice) and baking soda. This reaction produces carbon dioxide gas, which 
makes cakes light and airy. 

3. This is an example of a neutralization reaction because the reactants are an 
odour-causing substance of fish (an amine, which is a weak base) and an acid 
(lemon juice). 

Section 2: Lesson 3 

1 . A chemical change that occurs in nature is the production of methane gas (marsh gas) in 
marshes or bogs. Bacteria produce the gas in these bogs when the oxygen level is low. 
The appearance of marsh gas over a bog is evidence of a chemical change. 

Another chemical change that occurs in nature is the decrease in production of chlorophyll 
in leaves of deciduous trees in the fall. The change of colour of these leaves is the 
evidence that chlorophyll is no longer produced and the chemical reaction to produce 
food is no longer occurring. 

2. The appearance of the yellow colour in Figure 2.7 is evidence of a chemical change. 

3. Station 1: There will be an increase in temperature. 

Station 2: Gas bubbles will rise up each column. 

Station 3: There will be a colour change as the Rolaids or Turns tablet is added. 

Station 4: There will be an increase in temperature in (a), and a precipitate will form in (c). 
Station 5: There will be bubbling and fizzing in the drops of hydrochloric acid. 

Station 6: There will be bubbles of gas moving up through the hydrogen peroxide. 

Station 7: The blue litmus paper will turn red in the acid and remain blue in the base. 


Science 24 • Module 1 • Appendix 


103 


4. Answers may vary slightly. Temperature changes in Station 1 will vary. 


ants (colours 
s; and whethe 
lid, liquid, or gas) 


Evidence of 

emical Change 


Products (colours; 
odours; and whether 
solid, liquid, or gas) 


1 

• water (clear liquid) 

• Sani-Flush (blue liquid) 

• temperature increased 
from 21 °C to 24°C 

• blue liquid 

CM 

• water (clear liquid) 

• gas displaced water 
at top of each column 

• hydrogen gas and 
oxygen gas 

• colourless 

3 

(a) 

• hydrochloric acid 
(clear liquid) 

• Rolaids (white solid) 

• colour changed from 
yellow to blue 

(b) 

• blue liquid 

4 

(a) 

• calcium chloride 
(white solid) 

• water (clear liquid) 

(b) 

• sodium carbonate 
(white solid) 

• white solid formed in 
liquid and settled on 
the bottom 

• white solid settled on 
the bottom 

• clear liquid 

5 

• zinc (grey solid) 

• hydrochloric acid 
(clear liquid) 

• bubbles formed on 
zinc 

• hydrogen gas and 
zinc chloride 

6 

• hydrogen peroxide 
(clear liquid) 

• manganese dioxide 
(black solid) 

• bubbles formed 

• oxygen gas 

7 

• hydrochloric acid 
(clear liquid) 

• sodium hydroxide 
(clear liquid) 

• blue litmus turned red 
in acid 

• blue litmus stayed 
blue in base 

• hydrochloric acid 
(clear liquid) 

• sodium hydroxide 
(clear liquid) 


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5. a. Textbook questions 2 and 3 of “Analyze,” p. 33 

2. The gas released was oxygen gas. To test for oxygen gas, bring a glowing splint 
near the gas and see if it bursts into flames (Investigation 2-A). 

3. Hydrogen and oxygen were produced in the reaction at Station 2. 

b. Textbook question 5 of “Conclude and Apply,” p. 33 

5. A reaction stops when one of the reactants is used up. 

c. Textbook question 6 of “Extend Your Skills,” p. 33 

6. Examples of how recognizing chemical change can help keep you safe include 

• wearing rubber gloves when using corrosive cleaning agents, such as oven 
cleaners and toilet-bowl cleaners 

• knowing that an unextinguished campfire or carelessly discarded cigarette can 
start a forest fire 

• storing chemical products separately to prevent dangerous chemical reactions 
(For example, storing ammonium nitrate fertilizer with diesel fuel can cause a 
spontaneous fire. Also, storing ammonium nitrate near oven cleaners or bleach 
can produce poisonous ammonia gas if accidentally mixed.) 

• keeping a catalytic converter working properly on a vehicle, or keeping an 
engine well tuned can reduce emissions that harm the atmosphere 

6. Evidence that a chemical change has occurred include the following: 

• A different colour is produced. 

• An odour is detected. 

• Bubbles appear. 

• A solid (precipitate) forms. 

• Energy (such as light, heat, or sound) is given off. 

7. Answers will vary. Here are two examples: 

When bromothymol blue is added to hydrochloric acid, the colour of the solution turns 
yellow. Then when a Rolaids tablet is added to the solution, the colour changes to blue. 
This indicates that the solution has changed from acidic to basic. 


Science 24 • Module 1 • Appendix 


105 


8. Answers will vary. Here are two examples: 

When a small amount of hydrochloric acid is added to mossy zinc, bubbles appear on the 
surface of the zinc. Also, when manganese dioxide is added to hydrogen peroxide, 
bubbles appear. 

9. The solid is called precipitate. 

10. Textbook question 2 of “Check Your Understanding,” p. 34 

2. (b) hydrogen peroxide decomposes producing oxygen gas and water (Station 6). 


Section 2: Lesson 4 

1 . Rusting has a nearly unnoticeable energy change. 

2. Energy of motion (kinetic energy) and heat energy are the two types of energy that result 
from burning gasoline in a car engine. 

3. Examples of exothermic reactions are 

• burning gasoline in an engine 

• metabolism 

• rusting 

Examples of endothermic reactions are 

• photosynthesis 

• ammonium nitrate dissolving in water (cold packs) 

4. The evidence proving that the reaction is exothermic are as follows: 

• The space shuttle is moving (has kinetic energy). 

• Light energy is released. 

• Heat energy is released. 

5. The evidence proving that the reaction is endothermic is that the water between the flask 
and the stool freezes enough that the stool sticks to the flask. 


106 


Science 24 • Module 1 • Appendix 


6. a. The evidence proving that a reaction has occurred is the release of light and heat 

energy. 

b. The product formed is sodium chloride (NaCI), or table salt. 

7. Answers will vary. A sample procedure is given, 
step 1: Label one Styrofoam cup “Calcium Chloride.” 

step 2: Pour 50 mL of distilled water into a graduated cylinder. Record the temperature of 
the water. 

step 3: Add 10 mL of distilled water to the Calcium Chloride cup. 
step 4: Add 5 g of calcium chloride to the cup. 

step 5: Stir in the mixture, and record the temperature after 30 s, 1 min, 2 min, and 3 min. 

step 6: Dispose of the cup and its contents as instructed by your teacher. 

step 7: Add 50 g of calcium chloride to 50 mL of distilled water to a resealable plastic bag. 
Feel the effects of the chemical reaction. 

step 8: Repeat steps 1 to 7 for each of the remaining chemicals. 

8. Answers will vary. Sample data is given. 



Initial Temperature 
(°C) 


Highest/Lowest 
oerature Reached (°C) 

calcium chloride 

'• : . 

24 

64 

. ' ■ 

sodium chloride 

24 

20 

sodium acetate 

24 

50 

ammonium chloride 

24 

7 


Science 24 • Module 1 • Appendix 


107 


9. a. Textbook questions 1, 2, 3.a., 3.b., and 4 of “Evaluate,” p. 36 


1 Hot Packs and Cold Packs 



70 

60 

50 

40 

30 

20 

10 

0 

















































r 

"i ii 


,1 tQI 















mmm 11 mucii i aiui u 

1 hinh^ct/IrwA/nct irn 















MV^I 1 



ooi 1^1 1 aiui ^ 



















































































r 

















! 
















i 

i ! 

















! 

U 

















E 




calcium sodium sodium ammonium 

chloride chloride acetate chloride 


Chemical 


2. The calcium chloride produced the most heat according to the graph. The 
ammonium chloride absorbed the most heat. 


3. a. Calcium chloride is less expensive than sodium acetate for a hot pack. Sodium 

chloride is less expensive than ammonium chloride for a cold pack. 

b. None of the named chemicals pose a serious transportation problem. 

4. Answers will vary. You may choose calcium chloride for a hot pack since it is less 
expensive. You may choose ammonium chloride for a cold pack since it is more 
effective than sodium chloride. 

b. The reactions involving calcium chloride and sodium acetate are exothermic. The 
reactions involving sodium chloride and ammonium chloride are endothermic. 

10. Answers will vary. A sample procedure is given. 

step 1: Label one styrofoam cup “Calcium Chloride.” 

step 2: Pour 50 mL of distilled water (or tap water) into a glass or cup. Record the 
temperature of the water. 


108 


Science 24 • Module 1 • Appendix 


step 3: Add 2 tablespoons (30 mL) of water to the Calcium Chloride cup. 
step 4: Add 1 teaspoon (5 mL) of calcium chloride to the cup. 

step 5: Stir the mixture, and record the temperature after 30 s, 1 min, 2 min, and 3 min. 

step 6: Dilute the mixture in the cup with additional water, and wash the mixture down 
the sink. Throw the empty cup into the garbage. 

step 7: Add 50 g of calcium chloride and 50 mL of water to a resealable plastic bag. Feel 
the effects of the chemical reaction. 

step 8: Repeat steps 1 to 7 using the sodium chloride. 

1 1 . Answers will vary. Sample data is given. 





Highest/Lowest 
Temperature Reached (°C) 

calcium chloride 

24 

64 

sodium chloride 

24 

20 

sodium acetate 

24 

50 

ammonium chloride 

24 

7 


12. Refer to the answers to question 9. 

13. Textbook questions 1, 2, and 3 of “Check Your Understanding,” p. 37 

1 . Exothermic and endothermic reactions differ in that energy is released in an 
exothermic reaction and absorbed in an endothermic reaction. Exothermic and 
endothermic reactions are similar in that both chemical reactions involve changes to 
the reactants to produce new products. 

2. Exothermic reactions release energy. So if the amount of energy released is large and 
rapid, as in an explosion, the reaction can be quite dangerous. 

3. These reactions are exothermic because they release energy to provide motion or 
heat. 


Science 24 • Module 1 • Appendix 


109 


Section 2 Review 


1 . Textbook question 1 of “Reviewing Key Terms”, p. 38 


1. a. 

vii 

b. i 

c. V 

d. iii 

e. 

iv 

f. viii 

g. vi 

h. ii 


2. Textbook questions 5, 6, and 8 of “Understanding Key Ideas”, p. 38 

5. In a chemical reaction, the reactants are the chemicals that are combined to form new 
chemicals, called products. Reactants and products have different properties. 


6. Answers will vary. A sample answer is given. 


" . v _ ' 


1 

combustion reaction 

candle wax and oxygen 

carbon dioxide and water 

natural gas and oxygen 

carbon dioxide and water 

neutralization reaction 

baking soda and vinegar 

carbon dioxide and salt 


8. Not all chemical changes are obvious. One example is rusting. Rusting is exothermic, 
but the amount of energy released is small and measureable only with sensitive 
instruments. Examples of obvious chemical reactions are burning gasoline in a car 
engine and the temperature change in a hot or cold pack. 

3. Textbook question 10 of “Developing Skills”, p. 39 

10. The combustion of hydrogen in the presence of oxygen is a reaction that releases 
energy that can be used to provide the motion in a car or rocket engine. This reaction 
is particularly useful because the only product is water vapour. 

4. Textbook question 14 of “Critical Thinking”, p. 39 

14. The second reactant is hydrogen. 


110 


Science 24 • Module 1 • Appendix 


Section 3: Lesson 1 


1 . Things you have learned thus far about chemical reactions are as follows: 

• Chemical reactions can be simple (combustion of hydrogen fuel) or complex (taking 
an antacid). 

• Chemical changes can be obvious (a candle burning) or less noticeable (reactions 
that make a cake rise or iron rust). 

• Chemical reactions can occur immediately (explosions) or slowly (ripening of a 
banana). 

2. Chemists use word equations to represent chemical reactions because it is a convenient 
way to show which chemicals went into the reaction and which chemicals were produced. 

3. The standard format for writing a word equation is as follows: 

• The left side of the equation lists all the reactants. 

• The right side of the equation lists all the products. 

• An arrow points from the reactants to the products. It shows that something is 
produced during the chemical reaction. 

4. The purpose of the plus sign (+) is to separate the reactants and products when there are 
more than one of each. 

5. a. oxygen + glucose -> carbon dioxide + water + energy 

b. Oxygen and glucose produce carbon dioxide, water, and energy. 

c. There are two reactants and three products in the word equation. 

6. a. carbonic acid + calcium carbonate -> calcium hydrogen carbonate 
b. There are two reactants and one product. 

7. a. zinc + hydrochloric acid -> zinc chloride + hydrogen gas + energy 

b. You would observe the zinc dissolving and small bubbles of gas released. You would 
also observe an increase in the temperature of the solution. This shows that energy is 
released. 


Science 24 • Module 1 • Appendix 


111 


8 . Textbook questions l.a. and l.b. of “Check Your Understanding,” p. 43 

1 . a. Solid zinc and hydrochloric acid produce hydrogen gas and zinc chloride. 

b. Ammonium nitrate and sodium hydroxide produce ammonium hydroxide and 
sodium nitrate. 


Section 3: Lesson 2 

1. Chemists use patterns to group reaction types because it allows them to predict the 
product of an unknown reaction. It also helps them understand the behaviour of 
substances in a chemical reaction. 

2. a. magnesium + oxygen magnesium oxide + light + thermal energy (heat) 

b. The reactants are magnesium and oxygen. The product is magnesium oxide. (Light 
and thermal energy are not called products.) 

c. Two elements are used as reactants. 

d. The reactants combine to form a compound called magnesium oxide. 

3. In a simple composition reaction, two or more elements combine to form a compound. 

4. A + B -> AB 

5. Most simple composition reactions are exothermic. 

6. It is important to know if a reaction is exothermic or endothermic because exothermic 
reactions release energy. If the amount of energy released is large enough, it can be 
dangerous to the person conducting the reaction. 

7. a. water + electric energy — > hydrogen gas + oxygen gas 

b. The reactant is water. The products are hydrogen gas and oxygen gas. 

8. In a simple decomposition reaction, the products are always elements. 

9. CD — > C + D 

10. This means that simple decomposition reactions require energy to drive the reaction. 


112 


Science 24 • Module 1 • Appendix 


1 1 . Simple composition reactions are opposite to simple decomposition reactions. In a 
simple composition reaction, elements are combined to form a compound. In a simple 
decomposition reaction, a compound is broken apart into its elements. Most simple 
composition reactions release energy, whereas most simple decomposition reactions 
require energy. 

12. Chemists, today, have an extensive knowledge of reaction types and are able to predict 
the products of the reactions. They also have sophisticated laboratory equipment that 
protects them from the products of reactions. They also know the dangers of coming in 
contact with hazardous chemicals. 

13. a. Textbook questions 1, 2, and 3 of “Analyze,” p. 47 

1. Oxygen gas formed when hydrogen peroxide was decomposed. Note: Water is 
also produced in this reaction. 

2. The spoon began to lose its tarnish and return to its silvery appearance. 

3. A slight rotten eggs smell (the smell of sulfur) was evident. 

b. Textbook questions 1 to 5 of “Conclude and Apply,” p. 47 

1 . Oxygen gas was present. 

2. The chemical change resulted in water and oxygen gas produced from hydrogen 
peroxide. 


3. The glowing splint bursting into flames was evidence that oxygen gas was 
produced. 

4. The aluminum sulfide accounts for the rotten eggs smell. 

5. Evidence of a reaction included colour change of the spoon, a slight rotten eggs 
smell, and small yellow flakes deposited on the aluminum foil. 

14. a. gasoline (octane) + oxygen -> carbon dioxide + water vapour + energy 

b. The reactants are gasoline (octane) and oxygen. 

c. The products are carbon dioxide and water vapour. 


Note: The manganese dioxide does not take part in tne reaction, it acts as a cat olwo+ 
which is a substance that makes a reaction proceed but does not take part in th< 





Science 24 • Module 1 • Appendix 


113 


15. The six materials shown in Figure 3.7 are nylon stockings, nylon jacket (windbreaker), 
lipstick (cosmetics), nylon tent, nylon backpack, and a tire. 

16. The use of 76 L of petroleum to produce all the goods is probably a better use of the 
fossil fuel. The car will transport a maximum of five or six people the distance. The 
articles produced will provide items for many people. 

17. a. acid + base -> salt + water 

b. The reactants are the acid and the base. 

c. The products are a salt and water. 

18. a. hydrochloric acid + magnesium hydroxide -> magnesium chloride + water 
b. The other product is a salt. 

19. a. The substance forming the white cloud is ammonium chloride. 

b. Hydrochloric acid and ammonium hydroxide are combining to form this compound. 

20. Textbook questions 1 and 2 of “Check Your Understanding,” p. 49 

1 . The chemical reactions in (b), (e), and (f) show simple composition reactions. 

Note: (a) is a combustion reaction; (c) is a simple decomp 
neutralization reaction. 

Actually, the chemical reactions in (b), (e), and (f) are also 
involve oxygen. However, since the other reactant in each 
are not called combustion reactions. 

2. a. The first equation shows two elements combining to form a compound. The 

second equation shows a substance breaking down into its elements. 

b. The first equation shows the general form of a simple composition reaction. 

c. The second equation shows the general form of a simple decomposition reaction. 


osition reaction; and (d) is a 




combustion reactions, since they 
is not normally called a fuel, they 


114 


Science 24 • Module 1 • Appendix 


Section 3: Lesson 3 


1 . a. The symbol for hydrogen is H. 

b. The symbol for oxygen is O. 

c. There are two hydrogen atoms in this compound. 

d. There is one oxygen atom in this compound. 

e. There is no subscript for oxygen. This shows that there is only one atom of oxygen in 
the formula. 

f. The subscript (I) shows that the substance is a liquid at room temperatures and 
normal atmospheric pressure. 

2. The list of the names and symbols for all the chemical elements can be found in the 
periodic table. (A periodic table is given on the back cover of the textbook.) 

3. Each chemical element has a symbol consisting of one capital letter or one capital letter 
and one lower-case letter. 

4. A chemical formula gives the chemical composition of a compound. 

5. a. S Q , , + 8 Zn, . -> 8 ZnS, , 

8( s ) (s) (s) 

b. There are eight atoms of sulfur in the reactants. 

c. The rule used was to put the symbol for the metal (zinc) first, followed by the symbol 
for the non-metal (sulfur). The name of the non-metal is then changed to “ide” 
(sulfide). 

6. The subscript (aq) is used to indicate a substance dissolved in water. 

7. Common names are used for many substances because they are easier to use. They 
have also been around since before the international naming system was created. 

8. a. baking soda b. lye or caustic soda c. natural gas 



b. CaCO 


3 ( s ) 


c. SiO 


2 ( 8 ) 


Science 24 • Module 1 • Appendix 


115 


10. a. calcium, carbon, and oxygen 


b. silicon and oxygen 


c. potassium and chlorine 

11. Textbook questions l.a. and l.d. of “Check Your Understanding,” p. 51 

1. a. This chemical is present in chalk for writing on chalkboards, in blocks of limestone 
for building materials, and in marble flooring. It contains three different elements: 
calcium (one atom), carbon (one atom), and oxygen (three atoms). There are five 
atoms in the formula. A WHMIS symbol is not required. The common names for 
this substance is chalk, limestone, and marble; its chemical name is calcium 
carbonate. 

d. This chemical is used as a fuel in furnaces, some cars, and industry. The 

substance contains two different elements: carbon (one atom) and hydrogen (four 
atoms). There is a total of five atoms in the formula. The substance should be 
labelled with the flammable WHMIS symbols. The common name for the 
substance is natural gas; its chemical name is methane. 


Section 3: Lesson 4 

1 . The mass of the reactants would be the same as the mass of the products. 

2. Antoine Lavoisier used solid mercury(II) oxide as the reactant for his experiment. 

3. The products were oxygen gas and liquid mercury. 

4. a. Both experiments show that the mass of the reactants is equal to the mass of the 

products. 

b. The Law of Conservation of Mass describes the results of the experiment. It states 
that matter is not created nor destroyed in a chemical reaction. If you start with 10 g 
of reactants, you will end up with 10 g of products. 

5. Chemical equations show scientists the exact quantities of the reactants and the 
products. 

6. A subscript is a number or letter written at the bottom-right edge of the element’s 
symbol. The number shows how many atoms of the element there are in the chemical 
formula; the letter shows the state of the substance. 


116 


Science 24 • Module 1 • Appendix 


7. Textbook question 2 of “Solve These,” p. 53 


2. FeO, . — ^ Fe, . + O , , 

(s) (s) 2(g) 

step 1 : What elements are on the reactant side? 

The letters Fe and O are on the reactant side. Fe is the symbol for iron. O is the 
symbol for oxygen. 

step 2: How many atoms of each element are on the reactant side? 

There are no subscripts. This tells you that there is one atom of iron and one 
atom of oxygen on the reactant side. 

step 3: What elements are on the product side? 

There is an Fe and an O on the product side. 

step 4: How many atoms of each element are on the product side? 

There is no subscript with Fe. This means there is one atom of iron. O has a 
subscript— 2. So, there are two atoms of oxygen. 

step 5: Is this equation balanced? 

reactant side = 1 atom of iron, 1 atom of oxygen 
product side = 1 atom of iron, 2 atoms of oxygen 

No, the equation is not balanced because there are more oxygen atoms on one 
side of the equation. 

8. A coefficient is a number written in front of a chemical formula. A coefficient tells you how 
many atoms or molecules of each substance are present in the formula. 


Science 24 • Module 1 • Appendix 


117 


9. a. There are two molecules of water in the chemical equation. 

b. There is one molecule of oxygen on the right side of the equation. 

c. There are two molecules of hydrogen on the right side of the equation. 

d. There are four atoms of hydrogen and two atoms of oxygen on the left side of the 
equation. 

e. There are two atoms of oxygen and four atoms of hydrogen on the right side of the 
equation. 

f. The equation is balanced. There are the same number of atoms of each element on 
each side of the equation. 

10. Textbook questions 1, 2, and 3 of “Solve These,” p. 54 

1. 2 Mg, , + 0 o , . — > 2 MgO, , 

y (s) 2(g) a (s) 

step 1:The letters Mg and O are on the reactant side. Mg is the symbol for 
magnesium. O is the symbol for oxygen. 

step 2: On the reactant side, the coefficient 2 tells you that there are two magnesium 
atoms. The subscript 2 tells you that there are two oxygen atoms. 

step 3: On the product side, there is an Mg and an O. 

step 4: The coefficient 2 means there are two MgO molecules. This means there are 
two magnesium (Mg) atoms and two oxygen (O) atoms. 

step 5: reactant side = 2 atoms of magnesium, 2 atoms of oxygen 
product side = 2 atoms of magnesium, 2 atoms of oxygen 

Yes, the equation is balanced. 


118 


Science 24 • Module 1 • Appendix 


2. 2 Al, , + 3 T, , -> 2 All , . 

(s) 2(s) 3(s) 

step 1:The letters Al and I are on the reactant side. Al is the symbol for aluminum. I is 
the symbol for iodine. 

step 2: On the reaction side, the coefficient 2 tells you that there are two aluminum 
atoms. 

The coefficient 3 tells you that there are three I 2 molecules. 

3I 2 =I 2+ I 2+ I 2 

The subscript tells you there are two iodine atoms in each I 2 molecule. 

I 2 =1 + 1 

So, 3I 2 =(I + I) + (I + I) + (I + I) 

= 6 iodine atoms 

step 3: On the product side, there is an Al and an I. 

step 4: The coefficient 2 tells you that there are two AII 3 molecules. This means 2 Al 
and 2 I 3 . 

2 Al = Al + Al 

= 2 aluminum atoms 

2 =I 3 +13 

=(i+i+i)+(i+i+i) 

= 6 iodine atoms 

step 5: reactant side = 2 atoms of aluminum, 6 atoms of iodine 
product side = 2 atoms of aluminum, 6 atoms of iodine 

Yes, the equation is balanced. 


Science 24 • Module 1 • Appendix 


119 



step 1:The letters C, H, and O are on the reactant side. C is the symbol for carbon. H 
is the symbol for hydrogen. O is the symbol for oxygen. 

step 2: On the reactant side, there is one carbon atom. 

The subscript 4 tells you that there are four hydrogen atoms. 

The coefficient 2 tells you that there are two 0 2 molecules. 


step 3: On the product side, there is a C, an O, and an H. 
step 4: First, look at the C0 2 compound. 

There is one carbon atom. 

The subscript 2 tells you that there are two oxygen atoms. 

Now, look at the 2 H 2 0 compound. 

The coefficient 2 tells you that there are two H 2 0 molecules. This means 
2 H 2 and 2 0. 


step 5: reactant side = 1 atom of carbon, 4 atoms of hydrogen, 4 atoms of oxygen 
product side = 1 atom of carbon, 4 atoms of hydrogen, 4 atoms of oxygen 

Yes, the equation is balanced. 


2 0 2 = 0 2 + 0 2 

= (0 + 0 ) + (0 + 0 ) 


= 4 oxygen atoms 


2 H 2 = H 2 +H 2 

= (H + H) + (H + H) 


20 = 0+0 


2 oxygen atoms 


= 4 hydrogen atoms 


120 


Science 24 • Module 1 • Appendix 


1 1 . Textbook questions 1 and 2 of “What Did You Find Out?,” p. 55 


1 . Reactions 2 and 4 are not balanced. Reaction 2 has two oxygen atoms on the left side 
of the equation and three oxygen atoms on the right side. It also has four hydrogen 
atoms on the left side and two hydrogen atoms on the right side. Reaction 4 has two 
mercury atoms on the left side of the equation and one mercury atom on the right 
side. 

2. When the same number and types of atoms are present on both sides of the equation, 
the equation is balanced. Since the number and types of atoms are exactly the same 
on both sides, the mass of the substances on both sides must be the same as well. 

12. Textbook questions 1, 2, and 3 of “Check Your Understanding,” p. 55 

1. a. CL < + 2 KL -> 2 KCL . + T,\ 

2(g) (g) (g) 2(g) 


Reactants = Cl 2 + 2 KI 

| (CI + Cl) + (KI + Kl) 

= (Cl + Cl) + (K + 1) + (K + 1) 

= (Cl + Cl) + (K + K) + (I + 1) 

= 2 chlorine atoms, 2 potassium atoms, 2 iodine atoms 


Products = 2 KCI + 1 2 

= (KCI + KCI) + (I + I) 

= (K + Cl) + (K + Cl) + (I + 1) 

= (K + K) + (CI + Cl) + (l + l) 

= 2 potassium atoms, 2 chlorine atoms, 2 iodine atoms 


The equation is balanced. 


Science 24 • Module 1 


Appendix 


121 


b. 3 Li + 

(s) 


2H 2 °(.) 


— > 


2 LiOH + 


H 


2(g) 


Reactants = 3 Li + 2 H 2 O 

= (Li + Li + Li) + (H 2 0 + H 2 0) 

= (Li + Li + Li) + (H 2 +0) + (H 2 +0) 

= (Li + Li + Li) + (H + H) + O + (H + H) + O 
= (Li + □ + □) + (H + H + H + H) + (0 + 0) 

= 3 lithium atoms, 4 hydrogen atoms, 2 oxygen atoms 


Products = 2 LiOH + H 2 

= (LiOH + LiOH) + (H + H) 

= (Li + O + H) + (Li + O + H) + (H + H) 

= (Li + Li) + (O + O) + (H + H + H + H) 

\= 2 lithium atoms, 2 oxygen atoms, 4 hydrogen atoms 


Because there are three lithium atoms in the reactants and only two lithium atoms 
in the products, the equation is not balanced. 


c. Zn, + H SO m -+ ZnSO , . + H , , 

(s) 2 4(1) 4(s) 2(g) 


Reactants = Zn + H 2 S0 4 

= Zn + (H 2 +S + 0 4 ) 

= Zn + (H + H) + S + (0 + 0 + 0 + 0) 

= 1 zinc atom, 2 hydrogen atoms, 1 sulfur atom, 4 oxygen atoms 

Products = ZnSO. + H 2 

= (Zn + S + 0 4 ) + (H + H) 

= Zn + S + (0 + 0 + 0 + 0) + (H + H) 

= 1 zinc atom, 1 sulfur atom, 4 oxygen atoms, 2 hydrogen atoms 


The equation is balanced. 


122 


Science 24 • Module 1 • Appendix 



2. Equations are balanced to show what happens in a real reaction. The equation shows 
the number and type of atoms before and after a reaction. A balanced equation has 
the same number of each type of atom before and after the reaction. 

3. Reaction 1: decomposition reaction 
Reaction 2: combustion reaction 
Reaction 3: composition reaction 
Reaction 4: decomposition reaction 


Section 3 Review 

1 . The following three reactions were described: 

• combining hydrogen and oxygen to form water vapour and energy 

• breaking water down to form hydrogen gas and oxygen gas 

• burning natural gas to give water vapour and energy 

2. Three important points of the Law of Conservation of Mass are as follows: 

• Mass does not disappear. 

• Atoms are neither lost nor created. 

• mass of reactants = mass of products 

3. Five signs of a chemical reaction are as follows: 

• Chemical reactions either release or absorb energy. 

• Gases are given off. 

• A solid may form or disappear. 

• There is a colour change. 

• An odour may become evident. 

4. You can use a diagram, formulas (a chemical equation), and words to describe a chemical 
reaction. 

5. a. Twice as much hydrogen gas as oxygen gas is produced. 

b. There are two molecules of hydrogen for each molecule of oxygen. The ratio is 2 to 1 , 
which is the same as the amount of hydrogen produced compared to the amount of 
oxygen produced. 

c. The diagram shows that there are the same number of hydrogen atoms and the same 
number of oxygen atoms on both sides of the equation. 


Science 24 • Module 1 • Appendix 


123 


6. a. There is one atom of carbon on each side, four atoms of hydrogen on each side, and 

four atoms of oxygen on each side of the equation. 

b. Yes, the equation is balanced. There are the same number of atoms of each element 
on each side of the equation. 

7. a. Textbook questions l.a., I.c., and l.d. of “Reviewing Key Terms,” p. 56 

1 . a. Although two or more reactants are needed for a simple composition reaction, 
only one product results. 

c. Reactions follow patterns. Studying these chemical reactions helps a chemist 
know what to expect. 

d. If a chemical appears on the periodic table, it is a(n) element. 

b. Textbook questions 3.a., 3.C., and 6 of “Understanding Key Ideas,” p. 56 

3. a. The chemical name for salt is sodium chloride. Its chemical formula is NaCI, 

(s) 

c. The chemical name for natural sugar is glucose. The chemical formula is 

CgH^C^s) ■ The chemical name for table sugar is sucrose. The chemical formula 
is 

6. Symbols and common naming methods are used to write chemical equations so 
they can be recognized by chemists around the world. 

c. Textbook questions 8.a., 8.C., and 8.f., of “Developing Skills,” p. 57 

8. a. simple composition reaction 
c. simple decomposition reaction 
f. simple composition reaction 


124 


Science 24 • Module 1 • Appendix 


d. Textbook question 10 of “Problem Solving/Applying,” p. 57 


10. Mg w + 2 HCI (|) -> MgCI 2(s) + H 2(g) 

Reactants = Mg + 2 HCI 

= Mg + (HCI + HCI) 

= Mg + (H + Cl) + (H + Cl) 

= Mg + (H + H) + (Cl + Cl) 

= 1 magnesium atom, 2 hydrogen atoms, 2 chlorine atoms 

Products = MgCI 2 + H 2 

= (Mg + CI 2 ) + (H + H) 

= Mg + (Cl + Cl) + (H + H) 

= 1 magnesium atom, 2 chlorine atoms, 2 hydrogen atoms 
Yes, this equation is balanced. 

e. Textbook question 12 of “Critical Thinking,” p. 57 

12. No, 20 billion carbon atoms will react with only 20 billion oxygen molecules 

because 1 carbon atom reacts with only 1 oxygen molecule. This leaves 10 billion 
oxygen molecules left over. 

Section 4: Lesson 1 

1 . You may be familiar with these fossil fuels: 

• gasoline 

• natural gas 

• propane 

• diesel fuel 

• coal oil or kerosene 

• coal 

2. A combustion reaction usually gives off energy in the form of heat and light. 

3. a. The chemical energy of the combustion reaction is converted into kinetic energy to turn 

the wheels of the car. 


Science 24 • Module 1 • Appendix 


125 


b. octane + oxygen -> carbon dioxide + water vapour + energy 

c. The formulas in the chemical equation for the combustion of octane contain a larger 

number of atoms than the formulas in the equations previously studied. 

4. Evidence of Combustion in Part 1 

• The wax melted. 

• Heat and light was given off by the flame. 

• The flame went out when it was covered by the jar. 

5. Evidence of Combustion in Part 2 

• The wax melted. 

• Heat and light was given off by the flame. 

• The flame went out when it was covered by the jar. 

• The water rose up the jar. 

• Black soot formed inside glass jar. 

6. The water rose up the jar because something in the air inside the jar was used up. Also, 
the air inside the jar was heated and expanded when the candle was burning. After the 
candle went out, the air cooled and contracted. This also allowed the water to rise up the 
jar. 

7. Incomplete combustion occurs when there is a lack of oxygen. 

8. The products of a complete combustion of a fossil fuel are carbon dioxide (c0 2(g) j , 
water vapour |h 2 0 (q) j, and energy. 

9. The products of an incomplete combustion of a fossil fuel are carbon monoxide |cO (g) j , 
carbon |c (s) j, carbon dioxide, water vapour, and energy. 

1 0. Carbon monoxide is a colourless, odourless gas that is extremely poisonous. It combines 
with the blood in the body and does not allow the blood to absorb oxygen. 

1 1 . The carbon from incomplete combustion in a fireplace ends up as black soot along the 
inside of the chimney wall and on the inside of the fireplace walls and doors. 

12. The gases produced by all living things are carbon dioxide, water vapour, and methane. 
These gases are produced by industry and general human activities (e.g., rice paddies 
and domestic cattle). 


126 


Science 24 • Module 1 • Appendix 


13. Greenhouse gases help maintain an average global temperature of about +15°C. 

14. Scientists are concerned about climate change because there is evidence of a faster rate 
of temperature change in the past century than at any other time in Earth’s history. 

15. The burning of fossil fuels to heat homes, to provide energy for transportation and 
industry, and to generate electricity may be contributing to global warming. 

16. Points that support the scientific viewpoint that human activities are directly related to 
climate change may include the following: 

• A large amount of carbon dioxide, water vapour, and methane are being released 
into the atmosphere. 

• Carbon dioxide makes up a small percentage of the atmosphere, so the amounts 
added are significant. 

• Three-atom molecules— such as carbon dioxide (C0 2 ) , water vapour (H 2 0) , 
nitrous oxide (N 2 0) , sulfur dioxide (S0 2 ) , and ozone (0 3 ) —absorb heat very well. 

• There is evidence of Earth’s increasing temperature due to greenhouse gases over 
the past century. Greenhouse gases trap heat, causing the atmosphere to heat up. 

• Some people believe global temperature increases are responsible for increasing 
numbers of extreme events around the world (e.g., droughts, floods, melting of 
glaciers, and El Nino). 

17. Points that refute the scientific viewpoint that human activities are directly related to 
climate change may include the following: 

• Changing global climate is a natural phenomenon. 

• Detailed climate data have only been available for a short period of time (about 150 
years). 

• There is no convincing scientific evidence that human-made greenhouse gases are 
the cause of global climate change. Much of the cause may be due to volcanic 
eruptions, forest fires, and methane released by animals. 

• There are too many variables to accurately predict the cause and effect of global 
climate change. 


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127 


18. Answers will vary. You should have chosen one side and supported your choice with 
some of the points from those in the answers to questions 16 and 17. 

19. a. Sulfur dioxide |s0 2(g) j and nitrogen dioxide |N0 2(g) j are released into the 

atmosphere by both natural and human activities. 

b. Volcanoes, forest fires, vehicle exhaust, and industrial smokestacks are some of the 
sources of these pollutants. 


c. The products are sulfurous acid |hl 2 S0 3( ) j, nitric acid |hN 0 3( ) j , and nitrogen 

K)- 


monoxide 


20. The subscript (aq) is short for aqueous. It means dissolved in water. 


21 . The more accurate term for acid precipitation is acid deposition. 


22. Some statues, forests, and lakes have been affected by acid deposition. 

23. a. The pH range for acids is 0 to 7. 

b. Lemon juice is more acidic because it has a lower pH. 

24. When the vehicle exhaust was added to the indicator, the solution turned yellow. This 
showed that something in vehicle exhaust helps form an acid. 

25. a. Nitrogen from burning fuel and oxygen from the air combine to form nitrogen 

monoxide. 

b. Nitrogen monoxide is formed in the combustion chamber of the engine. 

c. Heat is also required to form nitrogen monoxide. 

26. Nitrogen monoxide gas and oxygen gas combine to form nitrogen dioxide. 

27. Nitrogen dioxide and water combine to form nitric acid and nitrogen monoxide. 

28. a. Nitrogen monoxide is a reactant in step 2. 

b. Nitrogen monoxide is a product in steps 1 and 3. 


29. The reactants of a fuel cell are hydrogen and oxygen. The only product is water vapour. 


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Science 24 • Module 1 • Appendix 


30. Sulfurous acid results from sulfur dioxide gas produced by the combustion of coal. 

31 . The purpose of a scrubber in the smokestack of a coal-burning plant is to remove sulfur 
dioxide from the emissions. 

32. The following is a summary of the acid deposition process described on pages 64 and 65 
of the textbook and on the Science. Connect 2 Student Multimedia CD. 

Volcanoes, burning forests, industry, and vehicles produce nitrous oxides (nitrogen dioxide 
gas and nitrogen monoxide gas). In vehicle exhaust nitrogen monoxide gas combines with 
oxygen gas at high temperature to form nitrogen dioxide gas. Nitrogen dioxide gas then 
combines with water to produce nitric acid and nitrogen monoxide gas. 

! 33. Textbook questions 2 and 4 of “Check Your Understanding,” p. 65 

2. Negative effects of global climate include 

• glaciers melting 

• sea levels rising 

• extreme weather patterns emerging 

• plants and animals unable to adapt to rapid temperature and precipitation changes 

4. Nitrous oxides (nitrogen dioxide and nitrogen monoxide) and sulfur dioxide are gas 
emissions linked to acid deposition. 


Section 4: Lesson 2 

1 . The hydrochloric acid comes from cells in the stomach. 

2. The stomach does not digest itself because certain cells in the stomach release a mucous 
that sticks to the wall of the stomach and neutralizes any acid that comes in contact with it. 

3. The pancreas produces sodium bicarbonate. 

4. Acidic food in the small intestine is neutralized with the sodium bicarbonate from the 
pancreas. 

5. hydrochloric acid + sodium bicarbonate -> sodium chloride + water + carbon dioxide 

HC| (aq) + NaHC0 3(aq) -> NaCI (aq) + H 2 0 (|) + C0 2(g) 


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129 


6. a. Liming is a technique used to neutralize an acidified lake by adding natural calcium 

carbonate (natural limestone). 

b. The purpose of liming is to neutralize the acid in the lake and raise the pH of the 
water. 

c. Liming is not a permanent solution because additional acid rain may decrease the pH 
again. The source of the acid rain must be removed to provide a permanent solution. 

7. The pH of acidic lake water is 4.5. The pH of neutralized lake water is 6.0. The change in 
pH is an increase of 1 .5 pH units. 

8. sulfuric acid + calcium carbonate solid calcium sulfate + carbon dioxide + water 

H 2 S0 4(aq) + CaC0 3(s) ^ CaS0 4 ( s ) + CC> 2(g) + H,,0 (|) 

9. Sulfur is removed from natural gas at the plant in Waterton. 

10. Coal mined in Alberta is valued because of its low sulfur content. 

1 1 . a. The process used to remove sulfur from the burning of coal is called sulfur scrubbing. 

b. Limestone |caC0 3(s) j is added at the start of the combustion of coal. The limestone 
will react with the gases without the use of water. In the final stages, calcium oxide 

^CaCO (s) j and water are injected into the smokestack emissions. The calcium oxide 
combines with the sulfur dioxide gas (SO , . I to form a slurry of calcium sulfite 

/ \ \ 2 W / 

( Cas0 *)- 

12. Sulfur scrubbing can remove more than 95% of the sulfur dioxide from smokestack 
emissions. 

13. Textbook questions 2 and 3 of “Check Your Understanding,” p. 68 

2. Fossil fuels are burned when driving a car, which produces nitrogen oxides in its 
exhaust emissions. These nitrogen oxides combine with water vapour in the 
atmosphere and return to Earth as acid deposition or acid precipitation. 

3. Liming a lake neutralizes some of the acids present in the lake water. This makes the 
lake water less acidic, therefore raising the pH of the lake water. 


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Science 24 • Module 1 • Appendix 


Section 4: Lesson 3 


1. Textbook question “Prediction,” p. 70 

An environmental factor responsible for corrosion of iron is the presence of moisture. 

2. a. Textbook questions 1, 2, and 3 of “Analyze,” p. 71 

1 . a. The water level in the test tube with the wet steel wool increased significantly. 

b. The water level in the test tube with the dry steel wool increased slightly. 

c. The water level in the test tube with no steel wool remained the same. 

2. The test tubes with wet and dry steel wool showed that something from the air 
inside the test tubes (oxygen) was consumed. 

3. The test tube with wet steel wool showed that water sped up the process of 
rusting, since more water moved up the test tube. Also, more rust was visible on 
the steel wool. 

b. Textbook questions 4 and 6 of “Conclude and Apply,” p. 71 

4. Answers may vary. The evidence gathered supports the prediction that moisture is 
an environmental factor responsible for rusting. 

6. You could prevent the rusting of metal, like steel wool, by keeping it dry and in an 
enclosed container. You could also coat the steel wool with a light oil to reduce 
rusting. 

3. Your completed table should be similar to the following. 


: 

i 

" ■ . ' '' • 


start 

at bottom of at bottom of at bottom of 

test tube test tube test tube 

after 24 hours 

, rose about rose about 

the same ^ 0 marks on 2 marks on 

graduated cylinder graduated cylinder 


Science 24 • Module 1 • Appendix 


131 


4. Refer to the answers to question 2. 

5. Corrosion is any process that chemically breaks down or degrades metal. 

6. The corrosion of steel and iron is a serious problem because it is so widely used as 
reinforcement in bridges and buildings. Over time, the corrosion of steel and iron in a 
structure weakens the structure. To repair or replace structures like bridges is expensive. 

7. a. 4 Fe + 3 O , — > 2 Fe ? C> , . 

(s) 2(g) 2 3(s) 

b. The reactants are iron and oxygen. 

c. Iron (III) oxide ^Fe 2 0 3(s) j is the product formed. 

d. Water is the additional substance not shown in the equation that is required for 
rusting. 

8. The reaction for rusting is a simple composition reaction. You know this because two 
elements combine to form a product. 

9. Gold is a metal that does not corrode. 

10. Textbook question 3 of “Check Your Understanding,” p. 71 

3. Both the combustion and corrosion of steel wool require oxygen. They both also have 
iron (III) oxide as the product. 

Section 4: Lesson 4 

1 . Painting reduces corrosion by preventing oxygen and water from coming into contact with 
the iron or steel. 

2. Painted iron or steel rusts anyway after a period of time because the paint cracks. This 
allows water and oxygen to reach the metal and start the process of corrosion. 

3. a. Galvanization is a process of applying a zinc coating to iron or steel. 

b. Galvinization prevents corrosion by coating the iron or steel object with zinc and 
preventing water and oxygen from reaching it. 


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Science 24 • Module 1 • Appendix 


c. Galvanizing is better than painting because the galvanized coating adheres very well to 
the iron or steel and actually becomes a part of the surface. 

4. a. A sacrificial metal is a metal attached to a metal object that corrodes to keep the metal 

object from corroding. 

b. Magnesium, zinc, and aluminium are common sacrificial metals. 

5. 2 Mg, + 0_, . -> 2 MgO, 

»(s) 2(g) a (s) 

6 . Textbook question 2 of “Check Your Understanding,” p. 73 

2. Painting a steel beam puts a protective coating on the beam, keeping water and 
oxygen from contacting the metal of the beam. This will prevent rusting, unless the 
paint cracks, chips, or is scratched off. However, metal beams are usually painted with 
a thin primer coat that will not crack or chip easily. 


Section 4 Review 

1 . Textbook question 1 of “Reviewing Key Terms,” p. 74 

1 . a. The two products of the combustion of gasoline are carbon dioxide gas and water 
vapour. 

b. Combustion reactions release energy and are classified as exothermic. 

c. The release of excess carbon dioxide gas into the atmosphere is thought to be 
associated with the greenhouse effect. 

d. Pollutants released into the atmosphere often bother people with asthma and other 
medical conditions. 

e. There are two possible answers. 

The pH of normal rainwater is 5.6. 

The pH of acid rainwater is 4.0. 


Science 24 • Module 1 • Appendix 


133 


f. There are two possible answers. 

Sulfurous acid is associated with acid deposition. 

Carbon dioxide is associated with global warming. 

g. The reactants of a neutralization reaction are an acid and a base. 

h. A scrubber is a technology that helps reduce the gases associated with acid 
deposition. 

i. The brown material flaking off the side of an old car is an oxide (rust). 

j. Iron nails can be protected from rusting by galvanization (and applying a polymer 
coating). 

k. Global climate change concerns many scientists because many species may not 
be able to adapt at the rate temperatures are currently changing. 

l. Acid deposition includes both dry matter and precipitation. 

2. Textbook questions 3, 4, 5, 6, and 8 of “Understanding Key Ideas,” p. 74 


3. sulfur dioxide + water -» sulfurous acid 


SO 


2(g) 


+ h 2 o ( i) 


H 2 so 3(aq) 


4. Health problems that may be aggravated by air pollutants include asthma; headaches; 
irritation of eyes, nose, and throat; heart conditions; and lung conditions. 


5. Carbon dioxide, methane, and water vapour are naturally occurring greenhouse gases. 

6. People take antacids when they have heartburn because the antacid neutralizes the 
excess stomach acid, making them feel better. 

8. Both processes require the presence of oxygen, and both processes are simple 
composition reactions. 


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Science 24 • Module 1 • Appendix 


3. Textbook question 11 of “Developing Skills,” p. 75 

1 1 . The following steps could be followed to determine if a new coating will prevent the 
corrosion of iron, 

step 1: Obtain two new, identical nails. 

step 2: Apply the new coating to one, and leave the other as is. 

step 3: Place both nails in an acid solution or in the presence of oxygen and water. 

step 4: After a period of time, inspect both nails for evidence of corrosion. 

4. Textbook question 13 of “Problem Solving/Applying,” p. 75 

13. The following steps could be used to determine if the compound would make a good 
ingredient for an antacid tablet. 

step 1: Obtain a sample of dilute hydrochloric acid to represent stomach acid, 
i step 2: Measure the pH of the dilute hydrochloric acid. 

step 3: Drop in the unknown tablet, and observe if a reaction occurs, 
step 4: Measure the pH of the mixture. 

If the pH increased, the compound should work as an antacid. (Other tests would have 
to be done to see if the tablet has any side effects.) 


Image Credits 

All images in this courseware were created by or for Alberta Learning with the following noted 
exceptions: 

Cover 

EyeWire Collection/Getty Images (burst in top-right corner); Digital Vision/Getty Images (windmills and semi); PhotoDisc 
Collection/Getty Images (all remaining photos) 

Title Page 

main: PhotoDisc Collection/Getty Images 

background: EyeWire Collection/Getty Images (burst in top-right corner); PhotoDisc Collection/Getty Images (all remaining 
photos) 

Welcome Page 

PhotoDisc Collection/Getty images 

Contents (two-page spread) 

top banner: PhotoDisc Collection/Getty Images (windmill, wheat, geese, and factory) 

bottom banner: Corel Corporation (lake); PhotoDisc Collection/Getty Images (vehicles, fox, welder, flower, and space 
shuttle) 


Science 24 • Module 1 • Appendix 


135 


Page 

6 banner: PhotoDisc Collection/Getty Images (lightning, 
pump well, and deer) 

7 banner: Digital Vision/Getty Images (wire); PhotoDisc 
Collection/Getty Images (sunflower and gas pump) 

8 banner: PhotoDisc Collection/Getty Images (leaves); 
Digital Vision/Getty Images (semi) 

9 banner: PhotoDisc Collection/Getty Images (water and 
power lines); Digital Vision/Getty Images (nuclear 
power plant) 

10 main: PhotoDisc Collection/Getty Images (cake) 
banner: PhotoDisc Collection/Getty Images (railroad 
crossing, soccer player, and light bulb) 

11 banner: PhotoDisc Collection/Getty Images (power 
pole, leaf, and sign 

12 main: Digital Vision/Getty Images 

14 EyeWire Collection/Getty Images (farm and teacher) 

16 EyeWire Collection/Getty Images 

18 PhotoDisc Collection/Getty Images (teacher) 

19 EyeWire Collection/Getty Images 

21 EyeWire Collection/Getty Images (student) 

23 PhotoDisc Collection/Getty Images 

24 PhotoDisc Collection/Getty Images 

26 © 2003-2004 www.clipart.com (make-up); EyeWire 
Collection/Getty Images (teacher) 

27 EyeWire Collection/Getty Images 

28 PhotoDisc Collection/Getty Images 

29 banner: Eyewire Collection/Getty Images (school bus); 
PhotoDisc Collection/Getty Images (cook and 
photographer) 

30 EyeWire Collection/Getty Images 

31 PhotoDisc Collection/Getty Images (purchasing food) 

32 EyeWire Collection/Getty Images (swimming and 
teacher) 

33 PhotoDisc Collection/Getty Images 

34 EyeWire Collection/Getty Images 

39 EyeWire Collection/Getty Images 

40 PhotoDisc Collection/Getty Images 

41 PhotoDisc Collection/Getty Images (teacher); EyeWire 
Collection/Getty Images (experiment) 

42 © 2003-2004 www.clipart.com 

43 PhotoDisc Collection/Getty Images (beaker); EyeWire 
Collection/Getty Images (teacher) 


48 PhotoDisc Collection/Getty Images 

50 main: Corel Corporation 

banner: Digital Vision/Getty Images (welder and steel 
mill); Corel Corporation (bridge) 

52 PhotoDisc Collection/Getty Images 

53 PhotoDisc Collection/Getty Images 

55 EyeWire Collection/Getty Images 

56 EyeWire Collection/Getty Images 

57 Digital Vision/Getty Images 

58 PhotoDisc Collection/Getty Images 

59 Digital Vision/Getty Images 

60 PhotoDisc Collection/Getty Images 

61 EyeWire Collection/Getty Images 

63 EyeWire Collection/Getty Images 

64 EyeWire Collection/Getty Images (student and teacher) 

65 EyeWire Collection/Getty Images 

66 EyeWire Collection/Getty Images (student and teacher) 

67 EyeWire Collection/Getty Images (teacher) 

69 main: PhotoDisc Collection/Getty Images 

banner: PhotoDisc Collection/Getty Images 
(smokestack, forest, and flames) 

71 PhotoDisc Collection/Getty Images 

73 PhotoDisc Collection/Getty Images 

74 Digital Vision/Getty Images 

75 PhotoDisc Collection/Getty Images 

77 PhotoDisc Collection/Getty Images (female teacher); 
EyeWire Collection/Getty Images (male teacher) 

78 Brand X/Getty Images (smokestacks); PhotoDisc 
Collection/Getty Images (teacher) 

81 PhotoDisc Collection/Getty Images 

82 © 2003-2004 www.clipart.com 

83 Digital Vision/Getty Images (painting); PhotoDisc 
Collection/Getty Images (teacher) 

84 PhotoDisc Collection/Getty Images 

85 main: PhotoDisc Collection/Getty Images 
banner: PhotoDisc Collection/Getty Images (cyclist, 
spider web, and leaf) 

87 main: PhotoDisc Collection/Getty Images 

background: EyeWire Collection/Getty Images (burst 
in top-right corner); PhotoDisc Collection/Getty 
Images (all remaining photos) 


136 Science 24 • Module 1 • 


Appendix 


Template for Which Dish Detergent Is Best? 


Title: 

Problem: 


Materials and Apparatus: 





Procedure: 















Science 24 • Module 1 • Appendix T1 



Conclusion: 


T2 


Science 24 • Module 1 • Appendix 





©2004