Teacher’s Guide
Thrilling
Expereiments
Chemical
Reactions
Grades 5-9
CRTV
CREDITS
Program Production
S u n b u r s t Vi s u a l M e d i a
Te a c h e r ’s G u i d e
Rose Bulau, M.Ed.
Heather Nelson
Print Material Design
Julie Fong
© 2004 Sunburst Visual Media, a division of Global Video, LLC
Hawthorne, NY 10532
Approximate running time: 18 minutes
Thrilling Experiments: Chemical Reactions
Table of
Contents
Guide Information ....................................05
Fast Facts..................................................07
Before Viewing Activities ..........................08
During Viewing Activities ..........................12
After Viewing Activities ............................16
After Viewing Quizzes ..............................20
Additional Resources ................................24
Answer Keys ............................................31
Script........................................................43
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Thrilling Experiments: Chemical Reactions
About This Guide
Guide
Information
Providing students with visual media is an excellent way to take them out of the
classroom and into the real world. Our programs offer real-world footage, dynamic graphics,
engaging dramatizations, and first-person testimonials that keep students interested and help
them visualize difficult concepts. More importantly, they reinforce critical learning objectives
shaped by state and national educational standards. However, the learning doesn’t begin and
end when the program does. You can make the learning experience even more effective by
using the materials provided in this Teacher’s Guide.
This guide is divided into the following sections:
• Fast Facts are designed to give your students a quick overview of the
information presented within the video.
• Before Viewing Activities help identify what students already know
about the subject, what they are curious about, and what they hope to learn.
• During Viewing Activities may be used during viewing to enhance
students’ understanding of the video.
• After Viewing Activities help students summarize and draw conclusions
from the information that was presented.
• After Viewing Quizzes test students’ retention of the information presented
in the program and activity sheets.
• Additional Resources are designed to help you extend the information
presented in the program into other areas of your curriculum.
• Answer Keys are provided for relevant activities or reproducible pages.
• Script content is provided in an unabridged version for future reference.
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Thrilling Experiments: Chemical Reactions
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Program Overview
Guide
Information
Thrilling Experiments: Chemical Reactions focuses on chemical reactions and their products.
The information presented by the narrator reviews chemical bonding and reactions, and
applies that learning to hands-on experiments that deal with the reactants and products of
chemical reactions.
Appropriate photos, graphics and illustrations enhance each experiment as well as live
action demonstrations of each experiment. The activities that correlate with this program will
enhance and extend students knowledge of chemistry and chemical reactions.
Viewing Objectives
After viewing the DVD/video and utilizing the activities provided in the Teacher’s Guide,
students will be able to:
• Understand and define key vocabulary words related to chemical reactions
• Use chemical equations to describe reactions
• Analyze energy changes involved in physical and chemical reactions
• Describe solutions in terms of composition, properties, and uses
• Predict how various factors affect the rate of a chemical reaction
• Classify substances as acids, bases or salts
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Thrilling Experiments: Chemical Reactions
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Chemistry Fast Facts
Fast Facts
• The word chemistry is derived from the Arabic word for gold making.
• Early Greeks and Chinese alchemists were the first to begin
experimenting with chemicals.
• The elements, molecules or compounds involved in chemical
reactions are called reactants.
• Mixing reactants in a chemical reaction form a new substance
called the product.
• In chemical reactions, the reactants create a new substance by forming
or breaking bonds.
• In covalent bonds, the reactants share a pair of electrons, with each reactant
contributing an electron.
• In ionic bonds, the atoms are held together by the natural attraction between
positive and negative charges.
• When a chemical reaction takes place, energy is either absorbed or released.
• An endothermic reaction absorbs heat.
• An exothermic reaction releases heat.
• If a gas or a liquid is released or a change in appearance
occurs when mixing reactants, a new substance has probably been formed.
• Catalysts are substances that control the rate
of chemical reactions.
• Enzymes are natural catalysts found in your body.
• Chemists use indicators to determine if a compound
has undergone a chemical reaction.
• Indicators help chemists determine the chemical
properties of a substance.
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Before Viewing
Activity 1
Name
Word Splash
Each of these words are related to chemistry. Write a paragraph using all of these words to
explain what you know about chemistry. Revisit this activity after viewing the program,
and correct any of the vocabulary you may have misused the first time. Compare your
paragraphs with the first attempt and note the differences.
alchemist reaction
com po und
olec
u le
m
element
catalyst
c
indicator
l
e
a
v
nt
o
ionic
ionic
ga
s
react
ant
c
i
m
r
e
h
t
o
d
en
e x o t h e r m i c
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Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Before Viewing
Activity 2
Name
Welcome to the Real World
In the space below, write a paragraph to answer the following question.
What are three examples of how you
see chemical reactions in the ‘real world’
and not just in science class?
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Before Viewing
Activity 3
Name
Did You Know That?
Read each fact and write a response to each question.
1. Knowing a bit of chemistry will help take the sting out of your next run-in with a
bee. When you get stung, a bee injects you with an acid. Apply a base using a
common material from your kitchen cabinet. What’s the best base to use and how would
you apply it to neutralize the acid from a bee sting?
2. Sometimes glass - or at least the means for making it - can fall from the sky. The
conventional way to make glass is to heat sand to very high temperatures and pour it
into a mold. But a mold and human involvement are not always needed. Around 1865,
a large meteorite fell in a remote area of the Saudi Arabian desert. Large amounts of
naturally occurring glass have been found in this area. How do you think this glass was
formed?
3. That nifty “sparks in the dark” trick with Wintergreen Lifesavers is really a
chemical reaction. When you bite into the candy and break its sugar crystals, they give
off electrons and give off ultraviolet light. But the chemical that gives the candy its flavor
(methyl salicylate) reacts with the ultraviolet light to make visible flashes of light. The
technical name for this process is triboluminescence. What do you think that means?
4. Michel Angelo relied on the power of chemistry to create his famous Sistine
Chapel. Like many artists before and after him, Michel Angelo painted frescos - the
technique of painting onto the wet plaster surface of a wall or ceiling. The lime (calcium
hydroxide) in the plaster reacts with the air as it dries, forming calcium carbonate. This
chemical reaction causes the paint to crystallize and become a part of the plaster. How
do you think this reaction has allowed frescos to last for hundreds of years?
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Thrilling Experiments: Chemical Reactions
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Before Viewing
Activity 4
Name
Show What You Know!
Often you know a lot about a subject before you begin studying it. Before viewing the
program, take some time to fill in the first two columns of the chart. After viewing the
program and completing some activities, revisit this chart and fill in the last two columns.
K
W
© Sunburst Visual Media, a division of Global Video, LLC
L
S
Thrilling Experiments: Chemical Reactions
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During Viewing
Activity 1
Name
Reaction Action!
While watching the video, complete the web to focus on the main points in the experiments
and other information from the program.
Catalysts
Endothermic
Reactions
Exothermic
Reactions
Release of
a Gas
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Thrilling Experiments: Chemical Reactions
C
H
E
M
I
S
T
R
Y
Indicators
Liquid to
Solid
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During Viewing
Activity 2
Name
Order It Up!
While viewing the program, watch for and record the steps taken during the
endothermic and exothermic experiments. The steps for each experiment are listed
below in the wrong order. Put them in proper order by writing the correct number in
the space provided.
Endothermic Reactions
_______
Add the water and stir.
_______
Put on safety glasses.
_______
Compare temperatures.
_______
Use a thermometer to check the temperature of the two reactants.
_______
Gather materials: 2 beakers, 1/4 cup ammonium nitrate, stirring
sticks, 2 thermometers, 2 cups of water.
_______
Check the temperature.
_______
Add the ammonium nitrate to the empty beaker.
Exothermic Reactions
_______
Continue measure temperature at regular intervals until the temperature
stops rising.
_______
Open the hand warmer packet.
_______
Record results.
_______
Measure the temperature of the empty beaker.
_______
Empty contents of packet into beaker.
_______
Gather materials: 1 beaker, 1 thermometer, 1 chemical hand warmer packet.
_______
Measure temperature of material in beaker.
_______
Put on safety glasses.
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During Viewing
Activity 3
Name
You’ve Got To Take The Good
With The Bad!
PMI Charts are a type of chart in which a student examines the Pluses, Minuses,
and Interesting things (or Implications) associated with a topic, decision, or idea.
While viewing the program, keep track of the pluses, minuses, and interesting
things you see and hear.
14
+
-
I
Pluses
Minuses
Interesting Thing
Thrilling Experiments: Chemical Reactions
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During Viewing
Activity 4
Name
Liquids to Solids
A color change is not the only physical change that can be seen when reactions take place.
While watching the liquids to solid experiment, record the effect of mixing the two liquids in
the chart below. In the top boxes, briefly describe the two chemicals used in the test. Then,
record your observations and answers in the other three boxes.
Chemical #1
Chemical #2
Describe the chemical reaction . . .
The physical change is . . .
Which creates . . .
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After Viewing
Activity 1
Name
Chemistry Vocabulary
Vocabulary words from the program are listed in the box below. Their corresponding
definitions are listed below the box. Match each word with its correct definition by writing
the word on the line. You may use any available resource to help you locate the correct
definition for each word.
alchemist
gas
chemical reaction
reactant
indicators
endothermic
catalyst
exothermic
covalent
compounds, elements,
and molecules
ionic
16
1. __________________________:
elements, molecules, or compounds in a chemical
reaction
2. __________________________:
a reaction that absorbs heat
3. __________________________:
this controls the rate of chemical reactions
4. __________________________:
just about everything that happens could be this
5. __________________________:
a type of bond in which the reactants share a pair
of electrons
6. __________________________:
these are involved in chemical reactions
7. __________________________:
a reaction that gives off heat
8. __________________________:
a bond in which atoms are held together
by natural attraction
9. __________________________:
ancient people who experimented with chemicals
10. __________________________:
this is released when a new substance is indicated
11. __________________________:
identify chemical properties
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
After Viewing
Activity 2
Name
Hidden Message Word Scramble
Chemistry related words, including some of your vocabulary words are scrambled
in the puzzle. Unscramble each word, and place the answer in the boxes next to the
scrambled word. Copy the letters in the numbered boxes to the corresponding boxes
at the bottom of the page to reveal the mystery message.
Turn chemicals into what?
NACSERTAT
3
23
NETCODHRMIE
25
19
8
15
LYATATSC
9
6
NIRTAECO
18
10
VNTEOCAL
17
12
NIOIC
24
5
RETHEMCIXO
2
13
22
HELCMTASIS
14
4
11
DONUCPOM
1
21
MEENLTE
20
7
LOCUELEM
16
1
2
3
4
5
17
18
6
7
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9
19
20
10
21
11
22
12
23
13
14
24
25
15
16
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After Viewing
Activity 3
Name
Finish It Off
Each of these statements were mentioned during the program. Using your
notes and other materials, complete the following sentences.
1.
Early Greeks and Chinese _____________________ were the first to begin
experimenting with chemicals.
2.
The elements, molecules, or compounds involved in chemical reactions
are called _____________________
3.
In _____________________ bonds, the reactants share a pair
of _____________________.
4.
When a chemical reaction takes place, energy is either
_____________________ or _____________________.
5.
An _____________________ reaction releases heat.
6.
Indicators help chemists determine the ____________________ ____________________
of a substance.
7.
When chemists want to know if a compound has undergone a reaction,
they use _____________________.
8.
An endothermic reaction _____________________ heat.
9.
In ionic bonds, the atoms are held together by the ____________________
____________________ between positive and negative charges.
10. A color change is not the only ____________________ ____________________
that can be seen when reactions take place.
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Thrilling Experiments: Chemical Reactions
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Name
After Viewing
Activity 4
Sum It Up!
Using the notes that you took on the graphic organizer web in During Viewing Activity 1, write
a summary of the information you learned from the program and the experiments. Try to
include the new vocabulary you learned in your summary.
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After Viewing
Quiz 1
Name
Vocabulary Matching Quiz
Match each vocabulary word with its correct definition by writing the letter of the word on
the line next to the definition.
A. atom
H. liquid
B. chemical reaction
I.
matter
C.
J.
molecule
compound
D. element
K. periodic table
E.
endothermic
L.
F.
exothermic
M. reactants
G. gas
physical property
N. solid
1.
_____: a physical state in which a substance has both volume and shape
2.
_____: an arrangement of chemical elements based on their atomic numbers
and similarity of properties
3.
_____: a physical state in which the substance has no definite volume or shape
4.
_____: a substance that is composed on one type of atom
5.
_____: the smallest particle of an element that has the chemical properties
of that element
6.
_____: a characteristic of a substance that can be observed, such as color, taste,
texture, and density
7.
_____: a chemical reaction in which heat is absorbed
8.
_____: a change in which two or more substance combine to form a new
substance or substances
9.
_____: the substances that combine in a chemical reaction
10. _____: a chemical reaction in which heat is released
11. _____: what substances are made of
12. _____: a substance made up of atoms of two or more elements
13. _____: a physical state in which a substance has definite volume,
but no definite shape
14. _____: the smallest unit of a compound that retains the chemical properties
of the compound
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After Viewing
Quiz 2
Name
Chemistry Quiz
Fill in the Blanks
Fill in the missing word or words to complete the sentences below.
1.
Chemists use _____________________ to determine if a compound has undergone
a chemical reaction.
2.
In chemical reactions, the reactants create a new substance by
_____________________ or _____________________ bonds.
3.
The word _____________________ is derived from the Arabic word for gold making.
4.
If a _______________ or a liquid is released or a change in _____________________
occurs when mixing reactants, a new substance has probably been formed.
5.
When a chemical reaction takes place, ____________________ is either
____________________ or released.
6.
____________________ are natural catalysts found in your body.
7.
The _____________________, _____________________, or _____________________
involved in chemical reactions are called reactants.
8.
Indicators help chemists determine the chemical ____________________
of a substance.
9.
In covalent bonds, the reactants share a pair of _____________________.
10. ____________________ are substances that control the rate of chemical reactions.
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After Viewing
Quiz 2
Name
Chemistry Quiz (cont.)
Fill in the Blanks
Fill in the missing word or words to complete the sentences below.
11. An _____________________ reaction absorbs heat.
12. Early Greeks and Chinese alchemists were the first to begin experimenting with
_____________________.
13. An exothermic reaction ____________________ heat.
14. In ____________________ bonds, the atoms are held together by the natural
attraction between ____________________ and ____________________ charges.
True or False
Circle the best answer for each question.
1. Exothermic reactions give off energy.
A. True
B. False
2. Endothermic reactions require energy.
A. True
B. False
3. Pick the true statement:
A. Catalysts are always permanently changed when they
speed up the rate of a reaction.
B. Catalysts are sometimes permanently changed when they
speed up the rate of a reaction.
C. Catalysts are never permanently changed when they
speed up the rate of a reaction.
4. Pick the false statement:
A. Catalysts are sometimes used to start a chemical reaction.
B. Catalysts are sometimes used to speed up a chemical reaction.
C. Catalysts are sometimes used to take part in a chemical reaction.
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After Viewing
Quiz 2
Name
Chemistry Quiz (cont.)
Multiple Choice
Circle the best answer for each question.
1. A physical change would be:
A. any change that does not result in new substances
produced with new or different properties
B. any change that does result in new substances produced
with new or different properties
C. none of the above
2. The difference between endothermic and exothermic processes is that:
A. exothermic processes involve the absorption of energy while endothermic processes
involve the emission of energy
B. endothermic processes involve the absorption of water while exothermic processes
involve the emission of water
C. exothermic processes involve the absorption of water while endothermic processes
involve the emission of water
D. endothermic processes involve the absorption of energy while exothermic processes
involve the emission of energy
3. What affects the rate of a reaction?
A. concentration
B. temperature
C. pressure
D. All of the above
4. Which substances exist before a chemical reaction?
A. products
B. reactants
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Extensions
Additional
Resources
• The periodic table is like a scientific alphabet. Have students prove
this statement through a multimedia presentation.
• A graphic organizer could be used to assist students in research on
chemists and their contributions to the science
• Several everyday items made from chemical reactions. Have
students look through household helpful hint books to locate
examples of everyday items made from chemical reactions and
create a guidebook to chemical reactions in our everyday lives.
• Have students investigate the mathematical formulas that are used for chemical reactions
and ionic and covalent bonding. They should then use the formulas to enhance their
understanding of the information presented in the video.
• Have students choose one element from the periodic table to give human qualities to and
to personify. Students should use the properties of the element to create the
characterization.
• Have students do a bit of creative writing. Would they rather be an ionic bond or a
covalent bond? Why? Be sure to have them explain their answers completely. Consider
developing this into a class debate that compares the two bonds.
• Complete a role-play of a chemical reaction. Have students create parts, build a script,
and present the role-play. Consider including roles such as the catalyst, the elements, the
molecules, the compounds, and the reactants.
• Investigate endothermic and exothermic reactions more completely. Research and locate
as many examples of the two types of reactions as possible. Find as many real-world
representations of these as possible and report back to the class.
• Recreate the liquids to solids investigation, as seen in the video. Use chemical terms and
formulas to explain the change that takes place. Consider presenting this investigation to
a younger class of students.
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Suggested Reading List
Additional
Resources
Bowden, Mary Ellen. Chemical Achievers: The Human Face of the Chemical Sciences Mary
Ellen Bowden, 1997 Designed to help teachers supplement science curricula with human
stories of discovery in the chemical sciences, Chemical Achievers presents the lives and
work of two types of achievers. First are the historical greats, those chemical scientists
most often referred to in introductory courses. Second are those scientists who made
contributions that are of special relevance to modern life and the career choices students
will make. The human faces summarized in this book range from Robert Boyle to Glenn
Seaborg and Stephanie Kwolek.
Budavari, Susan (Ed.) (1996) The Merck Index: An Encyclopedia of Chemicals, Drugs, and
Biologicals. Whitehouse Station, NJ: Merck.
Dean, John A. (1999) Lange’s Handbook of Chemistry. New York: McGraw-Hill. 15th Ed.
Available in print at:
Lagowski, Joseph J. (Ed.) (1997) Macmillan Encyclopedia of Chemistry. (4 vol.) New York:
Macmillan Reference USA.
Lewis, Richard J. (Ed.) (1997) Hawley’s Condensed Chemical Dictionary. New York: Van
Nostrand Reinhold. 13th Ed.
Lide, David R. (Ed.) (2000) CRC Handbook of Chemistry and Physics. Cleveland: CRC Press.
81st ed. Available in print at:
Schleyer, Paul von Rague. (Ed.) (1998) Encyclopedia of Computational Chemistry. (5 vol.)
New York: Wiley.
Springer, J. Beilstein Handbook of Organic Chemistry, Berlin : 1918. Beilstein Handbook is a
selective collection of published data on the preparation and properties of carbon
compounds. Most of the series is written in German. A point of use guide is available.
Beilstein Abstracts is available online (requires free registration).
Workman, Jerry. (2001) Handbook of Organic Compounds. (3 vol.) San Diego: Academic
Press.
Chemical Abstracts, Columbus, Ohio : American Chemical Society. 1907 Chemical Abstracts
is a comprehensive index to all aspects, pure and applied, of the field of chemistry.
Coverage from 1907 - present; indexes published weekly. A point of use guide is
available. See also SciFinder Scholar.
Handbook of Physical Properties of Organic Chemicals. 1997. Arranged by CAS Registry
Number, it includes tables of physical properties, pictures of structures, solubility in
water, pKa, vapor pressure and references. There is a molecular formula index and an
alphabetical name index.
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Suggested Reading List
Additional
Resources
Merck Index of Chemicals and Biologicals. 13th edition. [There is a CD-ROM version
available in the SL Reference Room.] Good for information on inorganic and organic
chemicals, drugs and pharmaceuticals. Has valuable information on organic compound
physical properties. Excellent source for information on colors, odors and crystal
shapes.
Names, Synonyms and Structures of Organic Compounds. 1997. Arranged by CAS
Registry Number. Features structures and molecular formulas. Includes a molecular
formula index and a name/synonym index. No physical properties are listed.
Lange’s Handbook of Chemistry. 15th ed. 1999. Chemical physical properties both for
inorganic and organic compounds. If you do not find the information in either the
Handbook of Chemistry and Physics, the Aldrich Catalog, or the Merck Index, this is the
place to look. Good source for “heats of formation.”
Dictionary of Organic Compounds. 5th ed. 1982. Arranged alphabetically by names, with
molecular formula, CAS Registry Number and name indexes. Ten supplements have
been published, each having self-contained indexes, as well as two cumulative indexes
for supplements 1-5 and 6-10. Good source for organic compound synonym names,
structures and physical properties. There is at least one reference for each compound
listed. Some derivatives for some compounds are available.
Dictionary of Inorganic Compounds. 1992. Arranged alphabetically by element. The
indexes are the best way to get into this tool. There is an element index, structural type
index, name index and CAS Registry Number index. Includes pictures of structures,
physical properties, name synonyms, molecular formula and at least one reference.
Dictionary of Organometallic Compounds. 2nd ed. 1995. vols 1-5. Arranged alphabetically
by element. The indexes are the best way to get into this tool. There is an index of
synthetic reagents, molecular formula index and CAS Registry Number index. Includes
pictures of structures, physical properties, name synonyms and at least one reference
Aldrich Library of FT-IR Spectra. 1993. vols. 1-3. Lists organic compounds arranged by
functional group families. The indexes are the best way to get into this tool. Molecular
formula index, alphabetical index and CAS Registry Number indexes are included.
Shows structures and spectra only, no physical properties.
Sigma Library of FT-IR Spectra. 1986. vols. 1-2. Focuses on biological-type compounds such
as peptides, amino acids or steroids. Shows structures and spectra only, no physical
properties. The indexes are the best way to access the material: alphabetical, molecular
formula and CAS Registry Number indexes.
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Suggested Reading List
Additional
Resources
Hawley’s Condensed Chemical Dictionary. 14th ed. 2001. . Everything you wanted to know
about basic chemistry concepts, elements and compounds in one place. Simple, easy, in
dictionary-style alphabetical arrangement.
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Internet Sites
Additional
Resources
Below are a list of sites that you may use to find more information about chemical
reactions. Due to routine web maintenance, not all of the links will be accurate at the
time of access. If the link is not available, try to conduct a search on that topic from
the main site or from a search engine.
The Catalyst
This is a site designed specifically for secondary education teachers, however all other
chemistry educators will surely find the site to be useful. In addition to providing a
somewhat extensive list of chemistry related links, the Catalyst is a place where teachers
can submit lessons that they have come up with and successfully used in a classroom
setting.
http://www.thecatalyst.org/
The Cavalcade o’ Chemistry
“Your one-stop chemistry shop!” This site contains useful information for students and teachers.
Students can get help using Mr. Guch’s helpdesk (practice worksheets, tutorial links, “Mr. Guch
Explains”), and teachers can get free labs, worksheets, and handouts from Mr.Guch.
http://www.chemfiesta.com/
Erik’s Chemistry
This site contains some very nice condensed notes covering most major topics in chemistry,
as well as organic chemistry. Included with a few of the notes are animated 3-D images.
http://members.tripod.com/~EppE/
General Chemistry Online!
An excellent chemistry web site with a little bit of everything. This site is one of the best on
the internet, both for content and quality.
.http://antoine.frostburg.edu/chem/senese/101/index.shtml
General Chemistry Web Course Tutorial
This site contains material relating to a first semester undergraduate course in general
chemistry. The visitor has access to lecture notes, practice homework, and practice exams.
There is also a site for second semester general chemistry.
http://wine1.sb.fsu.edu/chm1045/
High School Chemistry Sites
A page of links to assist teachers in planning classes and labs.
http://www.ced.appstate.edu/whs/goals2000/projects/rookie.htm
High School Hub Chemistry Guide
This site is part of the High School Hub and provides a nice list of web resources for
teachers or students.
http://highschoolhub.org/hub/chemistry.cfm
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Internet Sites
Additional
Resources
Home Page of Ralph Logan
A site for teachers and students of chemistry at various levels. It contains resource links
related to chemistry and math, as well as additional links for other science topics,
education, and the web. Moreover, contains text pages covering several topics related to
chemistry.
http://members.aol.com/profchm/
Paul’s Chemistry Lab
A good chemistry resource for students and teachers.
http://www.geocities.com/CapeCanaveral/Lab/5875/
“Ponder Chemistry” Lessons Index
This site provides several lessons for teachers to use.
http://www.lynchburg.net/hhs/chemistry/
Principles of Chemistry
This site presents information and exercises on selected topics in introductory chemistry to
the web-surfing chemistry students of the world.
http://vax1.bemidji.msus.edu/~chemistry/chemhome.html
Science Resource Center
This web site is for science teachers to share ideas. The author provides labs,
demonstrations, a Chemistry Exam Exchange Center (where teachers can download tests,
quizzes, and exams), and other information which teachers can access. Contributions are
welcome.
http://chem.lapeer.org/
SparkNotes Chemistry Study Guides
Free online study guide website.
http://www.sparknotes.com/chemistry/.dir/
Steve Marsden’s Chemistry Home Page
A very good chemistry resource for teachers and students. This site focuses on honors and
AP level chemistry.
http://www.chemtopics.com/
Teaching Our Youth Science (T.O.Y.S.)
The goal of this site is to provide secondary science teachers with ideas that use toys to
teach science concepts. The site is broken down into two main categories; chemistry and
physics. Teachers are encouraged to submit their own toy related teaching ideas by filling
out the survey form.
http://www.neenah.k12.wi.us/users/herttings/index.htm
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Internet Sites
Additional
Resources
Visionlearning
Visionlearning provides free, award-winning instructional lessons in modular form. They
have two levels of chemistry modules, covering many of the common topics in high school
chemistry. All of the modules in our library share consistent features to make navigation
simple and learning fun. The modules also incorporate a healthy mix of text, pictures, and
diagrams.
http://www.visionlearning.com
The Woodrow Wilson National Leadership Program in Chemistry
The WWNFF Leadership Program in Chemistry aims to provide teacher developed materials
that will enliven your classroom with exciting demonstrations, experiments, and student
activities.
http://www.woodrow.org/teachers/chemistry/
World Chemistry
This website is designed to support students who are studying advanced chemistry courses
in high schools around the world. The site is very nicely done, and contains a wealth of
information and features.
http://www.scormtech.com/chem/home/index.htm
30
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Answer Key - Before Viewing Activity Sheet 3
Did You Know That?
Read each fact and write a response to each question.
1. Knowing a bit of chemistry will help take the sting out of your next run-in with a
bee. When you get stung, a bee injects you with an acid. Apply a base using a
common material from your kitchen cabinet. What’s the best base to use and how would
you apply it to neutralize the acid from a bee sting?
Baking soda made into a paste
with water, and rub into the sting.
2. Sometimes glass - or at least the means for making it - can fall from the sky. The
conventional way to make glass is to heat sand to very high temperatures and pour it
into a mold. But a mold and human involvement are not always needed. Around 1865,
a large meteorite fell in a remote area of the Saudi Arabian desert. Large amounts of
naturally occurring glass have been found in this area. How do you think this glass was
formed?
Intense heat from the meteor
heated the sand, creating glass
3. That nifty “sparks in the dark” trick with Wintergreen Lifesavers is really a
chemical reaction. When you bite into the candy and break its sugar crystals, they give
off electrons and give off ultraviolet light. But the chemical that gives the candy its flavor
(methyl salicylate) reacts with the ultraviolet light to make visible flashes of light. The
technical name for this process is triboluminescence. What do you think that means?
Luminescence, or light, created by friction
4. Michel Angelo relied on the power of chemistry to create his famous Sistine
Chapel. Like many artists before and after him, Michel Angelo painted frescos - the
technique of painting onto the wet plaster surface of a wall or ceiling. The lime (calcium
hydroxide) in the plaster reacts with the air as it dries, forming calcium carbonate. This
chemical reaction causes the paint to crystallize and become a part of the plaster. How
do you think this reaction has allowed frescos to last for hundreds of years?
Answers will vary.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Answer Key - During Viewing Activity Sheet 1
Reaction Action!
While watching the video, complete the web to focus on the main points in the experiments
and other information from the program.
Produces a gas
Absorbs heat
Cold compress is
an example
Catalysts
Endothermic
Reactions
Moved slowly at
first
25 degree loss of
temperature
Gives off heat
Hand warmer
Exothermic
Reactions
85 degree
temperature
increase
C
H
E
M
I
S
T
R
Y
To see if a
compound has
had a reaction
Indicators
New Substance
created
Demo with baking
soda
Thrilling Experiments: Chemical Reactions
Tells chemical
properties
Color produced
Mixing Reactants
32
Produces a
change in
temperature
Physical changes
Release of
a Gas
Liquid to
Solid
Polymer created
Chemical reaction
occurred
© Sunburst Visual Media, a division of Global Video, LLC
Answer Key - During Viewing Activity Sheet 2
Order It Up!
While viewing the program, watch for and record the steps taken during the
endothermic and exothermic experiments. The steps for each experiment are listed
below in the wrong order. Put them in proper order by writing the correct number in
the space provided.
Endothermic Reactions
5
_______
Add the water and stir.
2
_______
Put on safety glasses.
7
_______
Compare temperatures.
3
_______
Use a thermometer to check the temperature of the two reactants.
1
_______
Gather materials: 2 beakers, 1/4 cup ammonium nitrate, stirring
sticks, 2 thermometers, 2 cups of water.
6
_______
Check the temperature.
4
_______
Add the ammonium nitrate to the empty beaker.
Exothermic Reactions
7
_______
Continue measure temperature at regular intervals until the temperature
stops rising.
4
_______
Open the hand warmer packet.
8
_______
Record results.
3
_______
Measure the temperature of the empty beaker.
5
_______
Empty contents of packet into beaker.
1
_______
Gather materials: 1 beaker, 1 thermometer, 1 chemical hand warmer packet.
6
_______
Measure temperature of material in beaker.
2
_______
Put on safety glasses.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Answer Key - During Viewing Activity Sheet 4
Liquids to Solids
A color change is not the only physical change that can be seen when reactions take place.
While watching the liquids to solid experiment, record the effect of mixing the two liquids in
the chart below. In the top boxes, briefly describe the two chemicals used in the test. Then,
record your observations and answers in the other three boxes.
Chemical #1
Chemical #2
Sodium Silicate
Ethyl Alcohol
Describe the chemical reaction . . .
A solid forms when the
liquids are mixed.
The physical change is . . .
Liquid to Solid
Which creates . . .
A polymer
34
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Answer Key - After Viewing Activity Sheet 1
Chemistry Vocabulary
Vocabulary words from the program are listed in the box below. Their corresponding
definitions are listed below the box. Match each word with its correct definition by writing
the word on the line. You may use any available resource to help you locate the correct
definition for each word.
alchemist
gas
chemical reaction
reactant
indicators
endothermic
catalyst
exothermic
covalent
compounds, elements,
and molecules
ionic
1. __________________________:
Reactant
elements, molecules, or compounds in a chemical
reaction
2. __________________________:
Endothermic
a reaction that absorbs heat
3. __________________________:
Catalyst
this controls the rate of chemical reactions
4. __________________________:
Chemical Reaction
just about everything that happens could be this
5. __________________________:
Covalent
a type of bond in which the reactants share a pair
of electrons
Compounds, Elements, and
6. __________________________:
Molecules
these are involved in chemical reactions
7. __________________________:
Exothermic
a reaction that gives off heat
8. __________________________:
Ionic
a bond in which atoms are held together
by natural attraction
9. __________________________:
Alchemist
ancient people who experimented with chemicals
10. __________________________:
Gas
this is released when a new substance is indicated
11. __________________________:
Indicators
identify chemical properties
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Answer Key - After Viewing Activity Sheet 2
Hidden Message Word Scramble
Chemistry related words, including some of your vocabulary words are scrambled in
the puzzle. Unscramble each word, and place the answer in the boxes next to the scambled
word. Copy the letters in the numbered boxes to the corresponding boxes
at the bottom of the page to reveal the mystery message.
Turn chemicals into what?
NACSERTAT
R E A C T A N T S
3
NETCODHRMIE
23
E N D O T H E R M I C
25
LYATATSC
19
8
15
C A T A L Y S T
9
NIRTAECO
R E A C T
I O N
18
VNTEOCAL
10
C O V A L
17
NIOIC
6
E N T
12
I O N I C
24
RETHEMCIXO
5
E X O T H E R M I C
2
HELCMTASIS
13
22
A L C H E M I
14
DONUCPOM
S T S
4
11
C O M P O U N D
1
MEENLTE
21
E
LOCUELEM
L
E M E N T
20
7
M O L
E C U L
E
16
C H E M I C A L S
1
2
3
4
5
F O R
17
36
18
Thrilling Experiments: Chemical Reactions
6
7
8
9
G O L D
19
20
21
I
S
A R A B
10
11
12
M A K
22
23
13
14
I C
15
16
I N G
24
25
© Sunburst Visual Media, a division of Global Video, LLC
Answer Key - After Viewing Activity Sheet 3
Finish It Off
Each of these statements were mentioned during the program. Using your
notes and other materials, complete the following sentences.
1.
Early Greeks and Chinese _____________________
were the first to begin
alchemists
experimenting with chemicals.
2.
The elements, molecules, or compounds involved in chemical reactions
are called _____________________
reactants
3.
In _____________________
bonds, the reactants share a pair
covalent
of _____________________.
electrons
4.
When a chemical reaction takes place, energy is either
_____________________
or _____________________.
released
absorbed
5.
An _____________________
reaction releases heat.
exothermic
6.
Indicators help chemists determine the ____________________
chemical ____________________
properties
of a substance.
7.
When chemists want to know if a compound has undergone a reaction,
they use _____________________.
indicators
8.
An endothermic reaction _____________________
heat.
absorbs
9.
In ____________________
bonds, the atoms are held together by the natural
ionic
____________________
between positive and negative charges.
attraction
10. A color change is not the only ____________________
____________________
physical
change
that can be seen when reactions take place.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Answer Key - After Viewing Activity Sheet 4
Sum It Up!
Using the notes that you took on the graphic organizer web in During Viewing Activity 1, write
a summary of the information you learned from the program and the experiments. Try to
include the new vocabulary you learned in your summary.
Answers will vary, but should indicate a general
understanding of chemistry and the terms discussed in the
program. Should be able to briefly describe each of the
six experiments.
38
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Answer Key - After Viewing Quiz 1
Vocabulary Matching Quiz
Match each vocabulary word with its correct definition by writing the letter of the word on
the line next to the definition.
A. atom
H. liquid
B. chemical reaction
I.
matter
C.
J.
molecule
compound
D. element
K. periodic table
E.
endothermic
L.
F.
exothermic
M. reactants
G. gas
physical property
N. solid
1.
_____:
N a physical state in which a substance has both volume and shape
2.
_____:
K an arrangement of chemical elements based on their atomic numbers
and similarity of properties
3.
_____:
G a physical state in which the substance has no definite volume or shape
4.
_____:
D a substance that is composed on one type of atom
5.
_____:
A the smallest particle of an element that has the chemical properties
of that element
6.
_____:
a characteristic of a substance that can be observed, such as color, taste,
L
texture, and density
7.
_____:
E a chemical reaction in which heat is absorbed
8.
_____:
B a change in which two or more substance combine to form a new
substance or substances
9.
_____:
M the substances that combine in a chemical reaction
10. _____:
F a chemical reaction in which heat is released
11. _____:
what substances are made of
I
12. _____:
C a substance made up of atoms of two or more elements
13. _____:
H a physical state in which a substance has definite volume,
but no definite shape
14. _____:
the smallest unit of a compound that retains the chemical properties
J
of the compound
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Answer Key - After Viewing Quiz 2
Chemistry Quiz
Fill in the Blanks
Fill in the missing word or words to complete the sentences below.
1.
Chemists use _____________________
to determine if a compound has undergone
indicators
a chemical reaction.
2.
In chemical reactions, the reactants create a new substance by
_____________________
or _____________________
bonds.
forming
breaking
3.
The word _____________________
is derived from the Arabic word for gold making.
chemistry
4.
If a _______________
or a liquid is released or a change in _____________________
gas
temperature
occurs when mixing reactants, a new substance has probably been formed.
5.
When a chemical reaction takes place, ____________________
is either
energy
____________________
or released.
absorbed
6.
____________________
are natural catalysts found in your body.
Enzymes
7.
The _____________________,
_____________________,
or _____________________
compounds
elements
molecules
involved in chemical reactions are called reactants.
8.
Indicators help chemists determine the chemical ____________________
properties
of a substance.
9.
In covalent bonds, the reactants share a pair of _____________________.
electrons
10. ____________________
are substances that control the rate of chemical reactions.
Catalysts
40
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Answer Key - After Viewing Quiz 2
Chemistry Quiz (cont.)
Fill in the Blanks
Fill in the missing word or words to complete the sentences below.
11. An _____________________
reaction absorbs heat.
endothermic
12. Early Greeks and Chinese alchemists were the first to begin experimenting with
_____________________.
chemicals
13. An exothermic reaction ____________________
heat.
releases
14. In ____________________
bonds, the atoms are held together by the natural
ionic
attraction between ____________________
and ____________________
charges.
positive
negative
True or False
Circle the best answer for each question.
1. Exothermic reactions give off energy.
A. True
B. False
2. Endothermic reactions require energy.
A. True
B. False
3. Pick the true statement:
A. Catalysts are always permanently changed when they
speed up the rate of a reaction.
B. Catalysts are sometimes permanently changed when they
speed up the rate of a reaction.
C. Catalysts are never permanently changed when they
speed up the rate of a reaction.
4. Pick the false statement:
A. Catalysts are sometimes used to start a chemical reaction.
B. Catalysts are sometimes used to speed up a chemical reaction.
C. Catalysts are sometimes used to take part in a chemical reaction.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Answer Key - After Viewing Quiz 2
Chemistry Quiz (cont.)
Multiple Choice
Circle the best answer for each question.
1. A physical change would be:
A. any change that does not result in new substances
produced with new or different properties
B. any change that does result in new substances produced
with new or different properties
C. none of the above
2. The difference between endothermic and exothermic processes is that:
A. exothermic processes involve the absorption of energy while endothermic processes
involve the emission of energy
B. endothermic processes involve the absorption of water while exothermic processes
involve the emission of water
C. exothermic processes involve the absorption of water while endothermic processes
involve the emission of water
D. endothermic processes involve the absorption of energy while exothermic
processes involve the emission of energy
3. What affects the rate of a reaction?
A. concentration
B. temperature
C. pressure
D. All of the above
4. Which substances exist before a chemical reaction?
A. products
B. reactants
42
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Script
CAST
Tony “Thrill” Hill ..............................................................host
June Sifuentes ......................................................experimenter
Zack ............................................................................volunteer
Lindsay ........................................................................volunteer
TONY
Hello and welcome to Thrilling Experiments! I’m your host, Tony “Thrill” Hill.
I’m glad you joined me. Today we’re going to do some thrilling experiments
as we work with some exciting chemical reactions.
You know, chemists have come a long way since the early Greeks and
Chinese first began experimenting with chemicals. Back in those days, people
sought to change one substance into another, such as lead into gold. As a
matter of fact, the word chemistry is derived from the Arabic word for gold
making!
Even though they never discovered a formula to make gold, the alchemists,
as they were called, paved the way for modern chemistry. In fact, some of the
specialized glassware designs they developed are still in use today.
Just about everything that happens around us is a chemical reaction. That’s
right, everything! Cars burning gasoline, food cooking on the stove, even the
air we breathe!
The elements, molecules, or compounds involved in chemical reactions are
called reactants. The reactants then form a new substance called the product.
Today we are going to perform some amazing experiments that deal with the
reactants and products of chemical reactions. But before we get into our
experiments, let’s do a quick review of chemical bonding and reactions.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
43
Script
In a chemical reaction, the reactants create a new substance. They do this by
forming or breaking bonds. These bonds are divided into two major types;
covalent and ionic.
In covalent bonds, the reactants share a pair of electrons. Each reactant
contributes an electron to the bond. In ionic bonding, the atoms are held
together by the natural attraction between positive and negative charges.
Similar to a magnet, you remember, opposites attract!
When a chemical reaction takes place, energy is always either released or
absorbed. When this happens things can get really interesting! To help us
today, we have science expert, June Sifuentes. Good to see you June!
JUNE
Thanks, Tony. We have some thrilling experiments to demonstrate today.
After I show you how, you may want to replicate them in your own classroom;
but remember, as with any experiment, the most important thing is safety!
NEVER attempt ANY experiment without proper supervision and equipment.
TONY
Good point June, We’ve got the proper equipment, so I think we’re ready for
our first experiment.
E XPERIMENT #1: ENDOTHERMIC REACTIONS
JUNE
Tony, before we begin, let me ask you a question. Have you ever twisted an
ankle?
TONY
Sure have! When I was playing soccer. It hurt like crazy!
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Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Script
JUNE
To ease the pain, your coach may have placed a bag filled with chemicals that
magically turned ice-cold on your ankle. Your coach was using what chemists
call an endothermic reaction. An endothermic reaction absorbs heat. In our
first experiment we will make our own cold compress.
TONY
This is gonna be awesome! What do we need?
JUNE
We’re going to need 2 beakers, ? cup of Ammonium Nitrate, stirring sticks, 2
thermometers, 2 cups of water, and a volunteer to help us.
TONY
Here’s our volunteer, what’s your name?
ZACK
I’m ZACK
JUNE
Well, the first thing we need to do is put on our safety glasses. We are going
to be working with chemicals and we need to be very careful with them.
First, use a thermometer to check the temperature of our two reactants, the
Ammonium Nitrate, and the distilled water.
ZACK
The ammonium nitrate’s temperature is 65 degrees. And the water’s
temperature is 60 degrees.
JUNE
Now, add the Ammonium Nitrate to our empty beaker. Next, add the water
and stir. Once they are well mixed, let’s check the temperature.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
45
Script
ZACK
Wow, look at that, it’s only 35 degrees! That’s a change of 25 degrees.
TONY
Almost like instant ice! No wonder cold generated from this reaction
is used to treat sports injuries.
JUNE
This was an endothermic reaction. Now, are you ready for an exothermic
reaction, one that generates heat?
TONY
YEAH! Let’s do it!
E XPERIMENT #2: EXOTHERMIC REACTIONS
JUNE
Now, an exothermic reaction is a chemical reaction that gives of heat. For this
experiment we’re going to need: a beaker, a thermometer, and a chemical
hand warmer packet, the type you might find at a sporting goods store or ski
shop.
The hand warmer packet contains a mixture of iron, water, cellulose, carbon,
and salt. When this mixture is exposed to the air, an exothermic reaction will
take place. OK, first, note the temperature of the beaker before we put the
reactant in it.
ZACK
It’s 65 Degrees fahrenheit.
JUNE
Good, now carefully open the packet, and empty its contents into the beaker.
Now check the temperature.
46
Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Script
ZACK
Wow, the temperature is rising really fast.
JUNE
Yes, it is. When the temperature stops rising, record it.
ZACK
It’s now 150 degrees. It rose 85 degrees.
JUNE
Great job. Thanks for helping. (to cam) As you can see, many times it’s very
evident that a chemical reaction has taken place, as with endothermic and
exothermic reactions.
E XPERIMENT #3: RELEASE
OF A
GAS
JUNE
Now, when you’re mixing reactants, and there is a release of a gas or liquid,
or the appearance of the reactants differ, a new substance has probably been
made. Our next experiment will demonstrate this
TONY
I think we better warn everyone that although this is not a dangerous
experiment, it can be quite messy. If you can’t protect your classroom or lab,
you might want to do this one outside! It’s a blast!
JUNE
Tony, while we head outside, I’ll let everyone know what we need. For this
experiment we need: a zipper-lock plastic bag that has no holes, a paper
towel or napkin, ? cup baking soda, ? cup vinegar, and ? cup warm water.
Also make sure you are wearing proper protection for your eyes and
clothing.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
47
Script
TONY
Ready!
JUNE
First, place your Sodium Bicarbonate (also known as baking soda) on a piece
of paper towel or napkin. You are going to make a kind of envelope for this
reactant.
TONY
Kind of like this?
JUNE
Perfect! Set that to one side for now. Next, combine our other reactants, the
water and the Acetic Acid (also known as vinegar), in the plastic bag. Now
here comes the messy part, are you ready?
TONY
You bet! This will be cool! OK, I’m adding the sodium bicarbonate envelope
to the bag! Whoa! That was cool!
JUNE
And there you have it! The product of our reactants was a gas, carbon
dioxide. So much carbon dioxide was produced that it burst our container.
EXPERIMENT #4
Catalysts
JUNE
Now let’s try a reaction that produces both a gas and a change in
temperature. A warning here; 30% Hydrogen peroxide is severely corrosive
to skin, eyes, and the respiratory tract. It must be handled and stored with
great care. Observe proper safety procedures. An adult might want to
perform this reaction rather than a student.
TONY
Ok, what do we need?
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Script
JUNE
This experiment requires; protective clothing, a 100 ml graduated cylinder, a
10 ml graduated cylinder, a large mixing beaker, a large, deep pan to
contain the product that will result from our reaction, 20 ml of 30% Hydrogen
Peroxide, 30 grams of sodium iodide (2 molar), distilled water, and
dishwashing liquid.
Place the 100 ml graduated cylinder in the pan. Dissolve 30 grams of the
sodium iodide in a large labeled beaker containing 100 ml of distilled water.
Set this solution aside.
Carefully measure 20 ml of 30% hydrogen peroxide into the empty
graduated cylinder. Be careful, this is much, much stronger than the hydrogen
peroxide that you might have in your medicine chest, and should be stored
and treated properly. Now add 7 ml of the dishwashing liquid to the 100 ml
graduated cylinder containing the 30% hydrogen peroxide.
TONY
Not much is happening at this point, but just wait!
JUNE
Carefully measure out 5 ml of the sodium iodide solution, using a clean 10
ml graduated cylinder. Carefully, yet quickly add the 5 ml of sodium iodide
solution into the 100 ml cylinder containing the hydrogen peroxide and
dishwashing soap.
Now STAND BACK!
TONY
This thing is really going crazy, look at the steam!
JUNE
The decomposition of the hydrogen peroxide creates heat and produces
oxygen gas. The foam is a result of the gas and water vapor mixing with the
dishwashing soap.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
49
Script
Did you notice that the reaction moved slowly at first? Once the sodium
iodide was added things really sped up. That’s because sodium iodide
acted as a catalyst. Catalysts are substances that control the rate of
chemical reactions. You have natural catalysts in your body called
enzymes. Enzymes speed up all kinds of reactions, like the breaking down
of food in your stomach! A lot of heat has been evolved in this experiment,
so make sure everything cools down before you clean this one up!
TONY
June, you mentioned that sometimes a chemical reaction results in a
product that looks different form the reactants. Can we try an experiment
that shows that?
E XPERIMENT #5: INDICATORS
IN
REACTIONS
JUNE
Sure Tony. When chemists want to know if a compound has undergone a
reaction they use indicators. An indicator tells the chemist what chemical
properties the substance has. This experiment will use the indicator
Phenolphthalein, which is a clear liquid.
For this experiment we need: phenolphthalein, sodium hydroxide, tannic
acid, distilled water, 2 large glasses, a mixing beaker, a stirring rod, and
a volunteer.
TONY
Here’s our volunteer. What’s your name?
LINDSAY
Hi! I’m Lindsay!
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Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Script
TONY
Thanks for coming. June, I recognize this from an old magician’s trick I
know! It was called changing water into wine. Only you would never want
to drink this stuff we make.
JUNE
Very important point Tony! Sodium hydroxide is lye - often used to open
clogged drains and very powerful stuff. The tannic acid is poisonous and
is dangerous if ingested or if inhaled.
First we need to fill the beaker with distilled water. Next, we’ll make the
water slightly basic by adding ? teaspoon of sodium hydroxide. Stir to
dissolve, leaving the liquid clear. Now, put a few drops of the
phenolphthalein into one of the empty glasses. Place a few drops of the
tannic acid into the other empty glass. Let’s begin our reactions by pouring
the water in the beaker into the glass containing the phenolphthalein
drops.
LINDSAY
Cool! Instant color! It is kind of like magic!
JUNE
Not really magic, just a chemical reaction- the phenolphthalein is colorless,
yet turns the water dark pink, indicating to chemists that the liquid is
alkaline, in other words, a base. Now pour our chemical ‘wine’ into the
water glass containing the acid.
LINDSAY
Wow, it went back to clear.
JUNE
The acid in the water glass was strong enough to return the solution
to acidic, the phenolphthalein indicator is again clear.
© Sunburst Visual Media, a division of Global Video, LLC
Thrilling Experiments: Chemical Reactions
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Script
TONY
Makes a good trick! Thanks for helping again.
E XPERIMENT #6: LIQUIDS
TO A
SOLID
TONY
So, are color changes the only physical change that can be seen when
reactions take place?
JUNE
No way, Tony! I’ve got a great experiment involving polymers to
demonstrate that. We are going to take two liquids, mix them, and form
a solid as the product. Are you ready?
TONY
You bet, what do we need?
JUNE
Since this experiment deals with a flammable liquid, and a corrosive
liquid we need to be very careful, and wear the proper safety gear. We’ll
need: chemical splash goggles, chemical resistant gloves, sodium silicate
solution (water glass, 20 ml), Ethyl alcohol CH3CH2OH (95%, 10 ml), a
small container, a 25 ml graduated cylinder, and a wooden stirring splint.
First, measure out 20 ml of the sodium silicate solution, and place it into
the container. Now add 10 ml of the ethyl alcohol to the container and
stir the mixture using the wooden splint. Use a steady circular motion as
you stir. A solid will form.
As the mixture thickens, transfer the solid to a gloved hand and begin to
squeeze the water from the ball. With the gloves still on, form the solid
into a ball.
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Thrilling Experiments: Chemical Reactions
© Sunburst Visual Media, a division of Global Video, LLC
Script
These two liquids have gone through a chemical reaction and produced a solid;
a very bouncy solid! Here, Tony try it out!
JUNE
Chemists are finding new ways to improve our lives nearly every day by
experimenting with chemicals. I hope you had fun today, bye!
TONY
Thanks, June. And thanks to you for joining us today. I sure learned a lot! We’ll
see you next time on Thrilling Experiments!
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Thrilling Experiments: Chemical Reactions
53