Countertop Chemistry
The Science House
North Carolina State University
The Science House
Box 8211
Raleigh, NC 27695
www.science-house.org
2005 Edition
Table of Contents
Introduction ........................................................................................ ii
Experiments
1. Dancing Spaghetti ................................................................................ 1
2. Combustion .......................................................................................... 3
3. Law of Conservation of Matter .............................................................. 6
4. Chromatography of Foods .................................................................... 10
5. Ziploc Bag Chemistry ........................................................................... 14
6. Floating Candles ................................................................................... 18
7. Production of Oxygen ............................................................................ 21
8. Production of Hydrogen ......................................................................... 23
9. Production of Carbon Dioxide ................................................................ 25
10. Single Replacement Reactions .............................................................. 27
11. Double Replacement Reactions ............................................................. 30
12. Gas Producing Reactions ....................................................................... 33
13. Red, White and Blue ............................................................................... 36
14. Rate of Solution ...................................................................................... 38
15. Ice Cream ............................................................................................... 42
16. Daffy Densities ....................................................................................... 45
17. Red, White and Blue II ........................................................................... 47
18. Oobleck .................................................................................................. 49
19. Gluep ...................................................................................................... 51
20. Clear Slime Polymer ............................................................................... 53
21. The Cat's Meow ...................................................................................... 55
22. Cabbage Juice Indicator ......................................................................... 57
23. Invisible Ink ............................................................................................. 60
24. The Witches' Potion ................................................................................ 62
25. What's in a Penny? ................................................................................. 65
26. Formulas Poker ....................................................................................... 68
27. Radioactive Decay of Candium ............................................................... 72
Appendix ........................................................................................................... 75
Introduction to Countertop Chemistry
There is a lot of interesting science to investigate in this world. Not all science is done
by men wearing white coats and working in laboratories. All of the world around us
involves science. A child or teacher can investigate some pretty interesting stuff without
requiring a laboratory or expensive laboratory equipment or dangerous chemicals.
These activities came from teacher training workshops that have been offered by The
Science House since 1992. Many teachers have taken the workshops and have applied
the activities in their own classrooms – from first grade to high school.
We believe that students should be involved in active learning in which the teacher acts
as a guide, not an answer machine. However, to be a good guide, the teacher has to
have the road map in her/his head. So these activities include directions for doing the
activities, suggestions on finding materials, and a little background on the science
involved.
We realize that there are no new science demonstrations under the sun. Many of these
may be experiments that you have seen before in another format. The point of this book
is to assemble them in a rational format that encourages you, as a student or teacher, to
try them out. A science demonstration in a book is useless until someone actually does
it and uses the experience to help her/his understanding.
The Science House is a science and mathematics learning outreach program of the
College of Physical and Mathematical Sciences at North Carolina State University. The
mission of The Science House is to work in partnership with K-12 teachers to emphasize
the use of hands-on learning activities in mathematics and science classes. The
Science House provides a variety of in-service training and enrichment activities that
reach students and teachers across North Carolina.
We are located on the Centennial Campus at North Carolina State University in Raleigh,
NC. For more information on our programs, please visit our website at www.sciencehouse.org, write to The Science House at Box 8211, NCSU, Raleigh, NC 27695-8211, or
email us at Science_House@ncsu.edu.
Fair Use Statement:
We make these materials available to teachers and students to encourage hands-on
learning in science. Teachers may freely reproduce these materials in hard copy as long
as the footer "The Science House, NC State University," is indicated.
Safety Statement:
Countertop Chemistry
The Science House, NC State University
ii
North Carolina State University and The Science House makes no warranty, explicit or
implied, as to the safety or suitability of these activities. We urge you to always use
proper safety equipment and precautions.
Acknowledgments
These activities are the results of contributions from a number of people. Melissa Cole
Brown wrote the first draft of the Countertop Chemistry activities. For this new, 2003
edition, Dr. Alton Banks and Dr. Catherine Banks have carried out a complete revision
and update of the activities. After teaching these workshops many times and being the
recipients of many helpful hints, we gratefully acknowledge the contributions of Rebecca
King, Mike Smith, Dr. Alton Banks, Dr. George Wahl, Todd Boyette, Bonnie Barnes
Bordeaux and Scott Ragan. We gratefully acknowledge the permission from Dr. Andy
Sae to allow us to adapt laboratories from “Chemical Magic From the Grocery Store.”
Countertop Chemistry
The Science House, NC State University
iii
Activities and Demonstrations
There are many ways to use these experiments. The students should do most of these
experiments so that they can see the phenomena "up close and personal" and try out
variations for themselves. Many of the activities are simple and cheap enough for the
students to bring home and show their parents. Educating parents is just as important
as teaching students!
You may wish to use some of the activities as demonstrations in which you do only one
setup of the activity and show it to the class. Be sure to make your demonstrations
interactive! Education research indicates that the presentation of information plays a
vital role in students’ acquisition of knowledge. Here are some tips about how to make
demonstrations more meaningful to your students:
Use students as helpers. If an activity requires Chemical A to be poured into Beaker B,
let Child C do the pouring, not the teacher.
Begin demonstrations by asking questions and by linking the demonstrations to the
related subject matter. This book has many questions for you to ask your students or
yourself.
During demonstrations, continue to ask questions to the students or allow them to
discuss the demonstrations with their classmates. ("What did you see?"; "What do you
think will happen if we do...?"; "Turn to your neighbor and explain what you just heard").
At the end of demonstrations, ask each student to write a three-sentence explanation of
what happened in the experiment and what they learned from it. Reading these
explanations after class will help you to better learn how to improve your use of
demonstrations and hands-on learning activities.
Each of the Countertop Chemistry activities can be used at a variety of grade levels.
Different grade students will learn different things from the activities. Therefore, some of
the questions included may be quite appropriate for first grade, whereas others may be
better suited for twelfth grade. Each activity includes directions, questions, materials
lists, and tips for carrying out the activity.
In conclusion, there are two simple rules that we have learned about doing
demonstrations or activities with students:
If it stinks, it is chemistry. If it is slimy, it is biology. If it does not work, it is physics.
If a demonstration works the first time, do not repeat it. If a demonstration does not work
the first time in front of your students, repeat it only once. Then give up.
Have fun!
Countertop Chemistry
The Science House, NC State University
iv
Experiment #1
Dancing Spaghetti
If you have ever cooked a spaghetti dinner, you may have
noticed that spaghetti noodles sink when placed into water.
This process happens because the noodles are more dense
than the water. This lab investigates why that principle
does not work with other solutions.
Materials
Substitutions
1- 1000 mL beaker
1
vase
 10 g sodium hydrogencarbonate
soda
 45 mL 3% acetic acid
 10-2 cm pieces of vermicelli
 Water

glass mixing bowl or
3 tsp. baking
4-5 tbsp. vinegar
Procedure
1. Fill your clear container 3/4 full with water. Add
the sodium hydrogencarbonate (or baking soda) and
stir to dissolve.
2. Break the vermicelli into 2-cm (one inch) pieces and
add them to the container.
3. Add the acetic acid (vinegar). If the vermicelli
does not begin to "dance" after a few minutes, more
sodium hydrogencarbonate and acetic acid should be
added.
*Raisins or mothballs can be used with similar results!
Countertop Chemistry
The Science House, NC State University
1
Experiment #1
Teacher's Notes
1. Vinegar (HC2H3O2) is a 5% solution of acetic acid.
It reacts with baking soda (sodium
hydrogencarbonate-NaHCO3), to produce carbon dioxide
gas (CO2) and sodium acetate (NaC2H3O2 ). The
reaction can be written as follows:
NaHCO3 (aq) + HC2H3O2 (aq) ------> CO2 (g) + H2O (l) + NaC2H3O2
(aq)
2.
Bubbles of carbon dioxide gas adhere to the surface
of the spaghetti. The result is that the density of
the spaghetti plus the gas is less than that of the
water solution so the pieces rise to the surface.
Many of the bubbles are released at the surface, and
the density of the spaghetti is once again greater
than that of the solution so the spaghetti sinks.
Children’s "water-wings" operate on the same
principle by increasing the volume of the child
without increasing the mass considerably.
3. Amounts of baking soda and vinegar are approximate
and depend on the type of container used. If a
larger container is used, increase the amount of
baking soda and vinegar appropriately.
Extensions
1.
Raisins or mothballs may be used in addition to, or
in place of, the spaghetti.
2.
Add a drop of food coloring to your water to enhance
the visibility of the "dance" movement.
Disposal
Solids may be placed in the trash and solutions may be
poured in the
sink.
Countertop Chemistry
The Science House, NC State University
2
Experiment #2
Combustion
This lab demonstrates why an object weighs more after
combustion occurs
rather than before it occurs.
Materials





Substitutions
Aluminum pie pan
Balance
Uncoated extra-coarse steel wool
Bunsen burner
Crucible tongs
Regular steel wool
LPG burner
Kitchen tongs
Safety Precautions
For your own safety wait until your teacher tells you
its ok before you light the burner. Turn on the gas
only after the match has been lighted.
This will
prevent an excess amount of gas from building up
around the burner. The heated steel wool will be very
hot and tongs must be used when handling it.
If the
pie pan becomes hot, it should not be put on the
balance until it cools.
Procedure
1.
Weigh the empty pie pan,
and record the mass in the Data section.
2.
Place a pad of the steel
wool (approximately 3 in. x 3 in.) in the pan and
record the weight of the pan and pad.
3.
Light the burner and adjust it to obtain a blue (hot)
flame.
4.
Hold the steel wool with the tongs and place it in the
flame for several minutes. Rotate the pad so that all
parts are exposed to the flame.
After all of the pad
has a dull gray appearance, turn off the burner.
Place the steel wool in the pie pan, sweeping any
"popped" pieces of the steel wool into the pie pan.
5.
Weigh the pan and steel wool, and record the mass.
Countertop Chemistry
The Science House, NC State University
3
Experiment #2
Data and Observations
1.
Weight of the empty pan:
__________g
2.
Weight of the pan and steel wool before heating:
__________g
3.
Initial weight of the steel wool (#2 - #1):
__________g
4.
Weight of the pan and steel wool after heating:
___________g
5.
Weight of the steel wool after heating
__________g
(#4 - #1):
6.
Difference between the weights of the steel wool
before and after heating (#5 - #3):
__________g
Questions
1.
2.
3.
What kind of change took place?
Why did the mass of the steel wool change as a result
of heating? Can you explain the differences in the
masses?
Write a balanced chemical equation for the burning of
steel.
Countertop Chemistry
The Science House, NC State University
4
Experiment #2
Extension
Try burning another metal, like magnesium or aluminum.
You may need to include the weight of the tongs
(initial and final) in this experiment as some of the
oxide will be left on the tongs.
CAUTION: When magnesium burns, it gives off a very
bright light. Don't look directly at the light!
Permanent eye damage may occur!
Write a balanced chemical equation for the burning of
the metal. How are the equations for the burning of
steel wool and magnesium (or aluminum) similar? How
can the oxidation of a metal (sometimes called
corrosion) be prevented?
Teacher's Notes
There is a gain in weight or mass when steel wool is
burned. The increase is due to the oxygen that
combines with the iron. The balanced chemical equation
for the combustion or oxidation of iron is:
4 Fe (s) + 3 O2 (g)
-------->
2 Fe2O3 (s)
The corrosion of iron is prevented by not allowing the
metallic object to be in contact with oxygen. This can
be accomplished by either painting, coating with oil,
or galvanizing the steel objects. Corrosion weakens
the iron because the iron oxide (rust) flakes off and
therefore reducing the amount of the steel. It is best
to use coarse to medium coarse steel wool. Fine steel
wool will give the effect of a "sparkler"--popping all
over the lab bench and possibly onto paper!!! Move
papers and towels away from the burner while heating
Students must use a sufficient amount of steel wool to
notice a change after heating. Caution students to
prepare for some popping of the steel filaments during
the experiment. The difference in mass will be very
small. An aluminum pie pan under the burner can be
used to collect the mass that has "popped".
Disposal
Used steel wools pads and pie pans may be placed
in the trash can.
Countertop Chemistry
The Science House, NC State University
5
Experiment #3
Law of Conservation of Matter
This experiment will explore whether matter is created or
destroyed during a chemical reaction.
Materials
Substitutions
Balance
4 graduated cylinders
3-150 mL beakers
0.1M solutions of: NaOH
solutions
CuSO4
and washing
NH3 (aq)
Na2CO3




4 (2 oz.) plastic cups
3 (5 oz.) plastic cups
Drano and ammonia
Bluestone algaecide
soda
Procedure
1.
Label the four graduated cylinders (or 2 oz. cups)
to contain the solutions (one each for NaOH, CuSO4,
NH3 (aq), and Na2CO3).
2. Use a graduated cylinder to measure about 60 mL (2
oz.) of the NaOH solution. Use a second graduated
cylinder to measure about 60 mL (2 oz.) of the CuSO4
solution and pour it into a 150 mL beaker (or 5 oz.
cup).
3. Carefully place the two containers on the balance.
Weigh the solutions and their containers together and
record their combined weight in the Data section.
4. Pour the NaOH solution into the container with the
CuSO4 solution. Allow the solutions to mix. Describe
what happens in the Data section.
5. Weigh both containers and the mixture again.
the new weight. Did the weight change?
Record
6. Repeat the process in steps 2 and 3 above, first
substituting NH3 (aq.) for the NaOH solution, then
substituting Na2CO3 for the NaOH solution. In each
case measure and record the masses as described in
steps 3 and 5 above.
Countertop Chemistry
The Science House, NC State University
6
Experiment #3
Data and Observations
Total Weight
Before
(g)
After
(g)
NaOH and CuSO4
NH3 (aq) and CuSO4
Na2CO3 and CuSO4
Observation of mixture:
Complete the following equations:
1. NaOH + CuSO4 ----> _________________________________
2. NH3 (aq) + CuSO4 ----> _______________________________
3. Na2CO3 + CuSO4 ----> ________________________________
Questions
1. What is the insoluble solid that is produced? Use a
solubility chart to predict the identity of the
insoluble product.
2. Use the periodic table to prove that total formula mass is
conserved.
Why is it important to balance a chemical reaction?
Extensions
Countertop Chemistry
The Science House, NC State University
7
Experiment #3
The substances chosen for this lab are common and easy
to find. You may want to repeat this lab with
solutions of:
Note that NEITHER iron(II) or zinc carbonates or
hydroxides are as insoluble as the copper(II) analog.
While Barium and lead salts have frequently been used
in this type experiment, the problems associated with
disposing of these materials suggest NOT USING either
of these salts in experiments.
Teacher's Notes
This experiment verifies the Law of Conservation of
Matter: Matter is
neither created or destroyed as a result of chemical
changes, but
may be changed in form.
The balanced equations are as follows:
 2NaOH (aq) + CuSO4 (aq) -----> Na2SO4 (aq) +
Cu(OH)2 (s)
 4NH3 (aq)) + CuSO4 (aq) -------> Cu(NH3)4SO4 (s)
 Na2CO3 (aq) + CuSO4 (aq) -------> Na2SO4 (aq) +
CuCO3 (s)
The insoluble product that is formed is called a
precipitate. Solubility Tables can help students
predict which product will be insoluble (form a
precipitate).
For additional ideas on this concept, see Experiment
#2 and the Teacher's Notes.
Solution Preparation
The sodium hydroxide can be obtained from Drano™ or
Red Devil™ Lye. If you use Drano, the solution does
not need to be very concentrated but you should filter
the aluminum filings that are mixed in with the
pellets of NaOH. Lye is CAUSTIC so wear gloves and
wash all surfaces anyone might touch.
Copper (II) sulfate can be purchased at a good
hardware or swimming pool supply store as an algaecide
(Bluestone) or root eater. Aqueous ammonia (formerly
Countertop Chemistry
The Science House, NC State University
8
Experiment #3
called ammonium hydroxide) is nothing more than
household ammonia, and can be used straight out of the
bottle from the grocery store.
Finally, the sodium carbonate can be purchased at the
grocery store as washing soda (Arm and Hammer brand)
and can be mixed with water to form a solution.
0.1
M solutions can be
prepared by dissolving the following masses of solid
into enough water to make 1-L of solution:
Copper sulfate
Sodium hydroxide
Sodium carbonate
25g
4 g
10.6 g
Safety Precautions
As mentioned in the solutions preparations section,
sodium hydroxide is CAUSTIC and should be handled
carefully. Students may need to wear gloves. The
base will feel slippery on the skin and should be
washed immediately. Copper solutions can cause eye
infections, so students should wash their hands after
handling these substances, too.
Disposal
All solids should be placed in trash cans. Most
solutions can be poured down the sink. Check your
local municipal water regulations concerning copper
sulfate, as some water regulators restrict the
concentration of copper (II) ions that can be poured
down drains.
Countertop Chemistry
The Science House, NC State University
9
Experiment #4
Chromatography of Foods
Chromatography is a separation technique for mixtures based
upon their relative affinities for stationary and mobile
phases. This technique will be practiced by separating a
mixture of FD&C dyes.
Materials
Large coffee filters
(15 cm)
 Toothpicks
 Jar lid (4 cm)
 Petri dishes
 Food coloring sets - 4
vials
Grape & Orange Kool-Aid
1 lb. bag of M&M's
Transparency pens
Pencil with graphitebased
led





Procedure
1. On a piece of filter paper, use a pencil to trace a
circle with the lid.
Top View
Side View
Filter paper (or coffee filter)
Hole for wick
1
4
3
wick
2
Pencilled circle
Locations for substances to be tested
spaced equally around circle
.
2. Use a pencil to number the spots on the filter paper
for each of the substances to be tested. Your teacher
will tell you how many positions you will need. Spread
out the numbers so they are equal distances apart.
3. Record the substances to be tested by their
appropriate number in the Data section.
4. For each of the substances to be tested place a small
dot on the penciled line by dipping a toothpick into
the colored liquid to be tested and touching the
paper. Allow the spot to dry and then re-spot in the
same position. (For the solids to be tested use the
Countertop Chemistry
The Science House, NC State University
10
Experiment #4
directions found in the Teacher’s Notes to prepare the
samples.)
5. Use the pencil to punch a hole in the center of the
coffee filter. Insert a folded piece of coffee filter
into the hole as a wick.
6. Add water to the Petri dish so that it is
approximately one-third full. Set the wick into the
water with the filter paper resting on top of the
disk. Allow the chromatogram to develop. The filter
paper itself must NOT touch the water in the Petri
dish.
7. For best separation of components, remove the
chromatogram BEFORE the water reaches the edge of the
filter paper (chromatograph). Record the colors in the
data table. What trends do you note? (Are there
primary colors in more than one sample?)
Data and Observations
Substance
Center
Middle
Edge
Tape your chromatogram on the back of this sheet.
Questions
1. What kind of change took place?
Was it chemical or
physical? How can you tell if the change was chemical
or physical?
What could you do to test this
hypothesis?
2. Why do we use chromatography?
3. How might a chemist use a similar process to analyze a
sample?
4. What do the words heterogeneous and homogeneous mean?
How do they apply to the substances in this lab?
Countertop Chemistry
The Science House, NC State University
11
Experiment #4
5. What are two other mixtures that can be separated by
ordinary physical means?
Countertop Chemistry
The Science House, NC State University
12
Experiment #4
Teacher's Notes
Directions for preparation of test substances:
1. CHARTREUSE- 12 drops yellow food coloring & 1 drop
green food coloring. Mix and apply to the paper strip
with a toothpick.
2. TURQUOISE- 5 drops blue food coloring & 1 drop green
food coloring.
3. M&M's- Place one drop of water on one M&M and use the
toothpick to apply the coloring from that drop of
water. Use a brown or tan M&M then repeat process for
a green M&M.
4. PURPLE SAURUS REX- Mix an entire packet of unsweetened
Kool-Aid with a few drops of water to make a thick
paste. Apply to the paper strips with a toothpick.
5. ORANGE KOOL-AID- Mix an entire pack of unsweetened
Orange Kool-Aid with a few drops of water to make a
paste. Apply to the chromatogram with a toothpick.
Recommended pens to use for this lab are: Vis-à-Vis™
transparency pens (black, blue, red, green) or Flair™ black
pens.
Results of Chromatographs:
Coloring
Center
Middle
Chartreuse
Turquoise
Brown M&M
Green M&M
Purple Kool-Aid
Orange Kool-Aid
Blue
Yellow
Yellow
Blue
Blue
Yellow
Edge
Red
Yellow
Red
Red
Answers to questions:
1. Chromatography is a physical change. Any of the
separated colors could simply be remixed in water.
Physical changes are reversible.
Countertop Chemistry
The Science House, NC State University
13
Experiment #4
2.
Chromatography is a method of separation for pigments or
dyes by using different rates of evaporation for the
component substances.
3.
Chemists can use more complex forms of this method to
analyze a sample to determine its contents.
4.
Homogeneous matter is the same throughout and exists
in only one phase of matter. Heterogeneous matter is
composed of a mixture of substances that can usually be
seen with the naked eye. Heterogeneous matter can be
separated by physical changes.
5.
Sand and salt can be separated by dissolving the salt
in water and
filtering the sand from the solution. Evaporation of
the water would
recover the salt. COLORED M&M'S can be separated by
moving the
differently colored pieces into separate piles.
Student Answers Will Vary
Safety Precautions
You should monitor the eating of the M&M's to be sure
that the students are not consuming the ones used for the
experiment or ones that have been handled in any way.
You might divide the candies by pouring some into a small
bathroom paper cup and pass them out to the students.
Disposal
All liquid materials may be poured down the sink.
sold materials
should be placed in a trash can.
Countertop Chemistry
The Science House, NC State University
All
14
Experiment #5
Ziploc™ Bag Chemistry
Three reactions are performed in a sealed Ziploc™ bag so
that the reactions can be easily observed.
Materials (per lab group)
Substitutions
4 Ziploc™ bags
1 tbsp. calcium chloride
30 mL water
2 tbsp. sodium hydrogencarbonate
soda
 35mm film canister (top optional)
paper cup
 30 mL Indicator solution (phenol red)
cabbage juice




Baking
Small
30 mL red
Procedure
1.
Add 2 tbsp. sodium hydrogencarbonate to a Ziploc
bag. Gently place a film canister (approximately 1/3
full of water) inside the bag in the upright position.
Squeeze out any excess air and seal the bag. Spill
the water into the bag by shaking. Look, listen, and
feel. Record your observations in the Data section.
2. Add 1 tbsp. of calcium chloride to a second Ziploc
bag. Repeat the remaining steps of step 1 for the
calcium chloride and record your observations for this
material.
3. Mix 2 tbsp. of sodium bicarbonate and 1 tbsp. of
calcium chloride in a third Ziploc bag and mix
thoroughly. Gently place a film canister
(approximately 1/3 full of water) inside the bag in the
upright position. Again, remove the excess air and
seal the bag. Spill the water in the canister by
shaking the bag. Look, listen, and feel!! Record
your observations in the Data section.
4. Repeat step 3, replacing the water in the film
canister with 30 mL of indicator solution.
Countertop Chemistry
The Science House, NC State University
15
Experiment #5
Data and Observations
1. Sodium hydrogencarbonate in water:
______________________
_______________________________________________
2. Calcium chloride in water:
____________________________
_______________________________________________
3. NaHCO3 + CaCl2 in water:
____________________________
_______________________________________________
4. NaHCO3 + CaCl2 with indicator solution:
___________________
_______________________________________________
Questions
1. Classify each of these changes as chemical or
physical. Use your
observations to help you make your decisions.
2. In the fourth bag, what did the indicator tell you
about the observed
reaction?
3. What gas is being produced? How could you test this?
4. Write an equation for any chemical changes that have
taken place.
5. Define heat of solution.
Countertop Chemistry
The Science House, NC State University
16
Experiment #5
Teacher's Notes
1. a) There is a physical change in the first bag. See
number 5 below
for explanation
b) A physical change occurs in the second bag.
c) In the third and fourth bags a chemical change
occurs. See note 4
for the equation.
2.
Phenol red can be used to show the presence of an
acidic solution.
It can be purchased at a swimming pool supply store.
Many foods
also contain indicators. One of these is red
cabbage juice.
3.
The indicator should show that the reaction
occurring in the third
bag is acidic. Cabbage juice will turn from red to
blue in color,
while phenol red will turn from red to yellow.
4.
The gas that is produced is carbon dioxide (CO2).
It is formed from
the carbonate ion, HCO3-. A burning splint would
show that the gas
extinguishes the flame. Some fire extinguishers use
carbon dioxide
for this reason.
5.
The chemical changes that occur in bags 3 and 4 can be
represented by
the following equation:
2NaHCO3 (aq) + CaCl2 (aq)-> CaCO3 (aq) + 2NaCl (aq) + H2O (l) + CO2 (g)
6.
A physical or chemical change may be accompanied by
a change of
energy. If the change requires heat from the
environment, it is said
to be endothermic.
Solute + Solvent + HEAT ---> Solution
7.
If it releases energy to the environment, it is said
to be exothermic.
Solute + Solvent
Countertop Chemistry
----> Solution + HEAT
The Science House, NC State University
17
Experiment #5
Safety Precautions
As the Ziploc bags expand, care should be used to
prevent excessive pressure build-up. The bags may
burst. When calcium chloride is dissolved in water heat
is given off, so care must be used with these solutions.
Disposal
Solid wastes may be placed in the trash can.
solutions may be
poured down the drain, followed by water.
Countertop Chemistry
The Science House, NC State University
All
18
Experiment #6
Floating Candles
Students will observe a combustion reaction and deduce the
components necessary for the reaction to occur. Students
will also observe the pressure/volume/# mol relationship
for gasses.
Materials







Substitutions
Water
Matches
Votive candle
Candle taper
2- 400 mL beakers
Beaker with water
Large Petri dish
2 -Small jars
Jar with water
Aluminum pie plate
Procedure
1. Place a votive candle in the center of an aluminum pie
pan and light it.
2. Carefully pour some water (food coloring optional)
into the pie pan until the candle is floating in the
water.
3. QUICKLY place the inverted jar over the candle and
allow it to rest on the bottom of the pie pan. Report
the result in the Data section.
4. Light the votive candle again and repeat steps 1-3.
Make sure you dry the inverted jar every time you
repeat this step.
5. List the sequence of events and the reason for each
result in the Data section. (Repeat steps 1-3 as
desired.)
Data and Observations
Sequence the events you observed:
1.
2.
3.
Countertop Chemistry
The Science House, NC State University
19
Experiment #6
4.
5.
Questions
Use your knowledge of the gas laws and the principles of
combustion to explain the observations listed above.
Countertop Chemistry
The Science House, NC State University
20
Experiment #6
Teacher's Notes
1. The correct sequence of events would be:
a) The volume of gas in the jar will expand.
b) Some condensation may form on the glass
c) The candle will go out.
d) The water level will rise as the hot gasses cool.
2. The explanation of the events is:
a) As the candle burns, the gas above it is heated
and therefore expands.
b) This behavior is known as Charles’ s Law.
c) Condensation is a product of the combustion
reaction, and can be formed when the warm moist
gas comes in contact with the cool glass surface.
d) Combustion reactions require the presence of
oxygen. When the candle has reacted with all of
the available oxygen, the candle will go out.
After the reaction has ceased, the heat from the
combustion is no longer produced. Therefore the
gas cools and contracts. The water then returns
to the jar. This behavior is stated in the gas
law known as Boyle’s Law.
3. Students must use dry candles and glassware to be
successful. You may want to have towels and extra
candles on hand.
4. When this experiment is performed as a demo, (with a
glass pie pan)
the jar will rattle at first. This gives evidence
that expanded hot air
is escaping in the jar.
Disposal
All solid materials may be placed in the trash can and
the liquids may be poured in the sink.
Countertop Chemistry
The Science House, NC State University
21
Experiment #7
Production of Oxygen
This experiment allows the student to generate oxygen gas
and to test some of its properties.
Materials







Substitutions
3% hydrogen peroxide (H2O2)
Yeast
125 mL Erlenmeyer flask
small jar
Stopper
Wood splints
toothpicks
Candle and matches
Teaspoon
lid
Procedure
1.
Pour approximately 100 mL of 3% hydrogen peroxide
into the flask.
2. Light the candle in preparation of studying the gas.
3. Add 2 tsp. of yeast to the H2O2 and cover loosely with
the lid. Bubbles of gas should begin to form.
4. Light a splint and allow it to burn for a few seconds.
Extinguish the flame so that the splint is glowing.
5. Immediately, remove the lid and insert the glowing
splint into the neck of the jar. Note the result.
Replace the lid and collect more gas.
6. Repeat step 4 to retest the gas.
Questions
1.
Write the equation for the reaction that occurs in
the above experiment.
2. What happened when the glowing splint was placed near
the opening of the glass jar?
3. Why must the container be closed during the
experiment?
4. What chemical property of oxygen gas does this
experiment demonstrate?
Countertop Chemistry
The Science House, NC State University
22
Experiment #7
5. List any precautions that should be used if high
concentrations of oxygen are present (ex. oxygen for
hospital patients).
Countertop Chemistry
The Science House, NC State University
23
Experiment #7
Teacher's Notes
In 1774 Joseph Priestly first prepared oxygen. This was
accomplished by focusing sunrays on mercury(II) oxide,
producing liquid mercury and a gas. Priestly discovered
that the gas made a candle burn more brightly. Lavoisier
determined the role oxygen plays in combustion and
respiration. Nearly all commercial oxygen is obtained from
separation of air. This method is chosen because of the
abundance of starting material and the ease isolation of
the pure oxygen. In this experiment oxygen is produced
from the decomposition of hydrogen peroxide into oxygen and
water.
YOUR HYDROGEN PEROXIDE MUST BE FRESH. H2O2 loses oxygen
when it is exposed to heat or light. Liver can also be
used as a catalyst for an interesting twist. When peroxide
is used to sterilize a wound, the peroxide decomposes to
release oxygen. Both enzymes in the liver and in the metal
ions are catalysis of this reaction.
1. Yeast is a catalyst for this decomposition and
therefore can be written over the reaction arrow:
2H2O2 (aq) + yeast ---> 2H2O (l) + O2 (g)
2. The splint will reignite when placed in the flask,
because oxygen supports combustion. Combustion is the
chemical combination of a substance with oxygen. An
oxide is one of the products.
3. The container must be stoppered (or closed in some
manner) to avoid loss of the oxygen, which is less
dense than air. Without the stopper the oxygen would
escape into the room.
4. The atmosphere is composed of 21% oxygen. If this
percentage were increased, any combustion process
would proceed at a greater rate.
Safety Precautions
1. The flask may become hot due to the exothermic nature
of the reaction. Use care when handling.
2. Oxygen gas is flammable! No open flames or sparks
should be near the gas production or storage area.
Disposal
All solid material can be placed in a trash container. All
solutions may be poured down the sink.
Countertop Chemistry
The Science House, NC State University
24
Experiment #8
Production of Hydrogen
The procedure will allow the student to generate hydrogen
gas and examine some of its properties.
Materials
Substitutions







Mossy zinc
galvanized nail
3 M hydrochloric acid
muriatic acid
125 mL Erlenmeyer flask and stopper
small jar
Stopper
lid
Wood splint
toothpick
Beral pipettes
droppers
Candle and matches
Procedure
1. Place a small amount of mossy zinc or a galvanized nail
in the flask.
2. Add one dropper full of HCl (aq) to the zinc. Gas
bubbles will be produced. Stopper the flask loosely.
3. After 20 seconds, light the wood splint from the candle,
and prepare to test for the gas.
4. CAREFULLY place the burning splint at the mouth of the
flask. Be prepared for the reaction! Replace the lid a
wait for more gas to collect.
5. Re-light a splint and test the gas again.
Questions
1. Write the equation for the production of the gas in the
above experiment.
2. Describe the reaction between the gas and the burning
splint.
3. Why must the container be stoppered in order for the gas
to be
collected?
4. What property of hydrogen made it less desirable as the
fill gas for the large dirigibles of the 1920’s and
1930’s?
Countertop Chemistry
The Science House, NC State University
25
Experiment #8
Teacher's Notes
During the sixteenth century a Swiss-German physician
named Paracelsus noted that a flammable gas was formed
when iron reacted with sulfuric acid. He did not realize
that the gas was a pure substance. In 1766, Cavendish
determined that the flammable material was a distinct
substance when he was able to produce the gas by reacting
a variety of acids with several metals. However, it was
Lavoisier who named the gas hydrogen, which means, "water
producer".
Hydrogen is produced when an active metal replaces this
element in hydrochloric acid. This reaction is called a
single replacement reaction:
2 (aq) + H2 (g)
Hydrogen has a density less than air, so we must use a
stopper or lid to keep it from escaping. For large
commercial ventures hydrogen is generally produced by the
electrolysis of water. Hydrogen is liberated at the
cathode when a direct current is passed through water
containing a small amount of an electrolyte.
Solution Preparation
Commercial muriatic acid is a strong acid and therefore
must be used with care! Gloves may be worn when working
with this chemical. To prepare a 3M solution: slowly add
100 mL of concentrated muriatic acid to 300 mL of
(distilled) water. This mixture will get HOT.
Safety Precautions
1. Proper eye protection should be used at all times.
2. Hydrochloric acid is corrosive. Proper care should
be used to protect skin and clothing.
3. If you are using glass bottles or jars, the
containers should be wrapped with tape to avoid glass
fragments if the container is broken or explodes.
4. Hydrogen gas is very reactive! Do not have open
flames or sparks near gas production or storage area.
Pressure will build up quickly inside the flask or
jar, so the container should never be tightly sealed.
Disposal
All solids may be placed in the trash can. Acid solutions
should be poured down the sink followed by water to clear
the plumbing.
Countertop Chemistry
The Science House, NC State University
26
Experiment #9
Production of Carbon Dioxide
Carbon dioxide can be produced with common household
chemicals. This experient observes some of its easily
observable properties.
Materials






Substitutions
Sodium hydrogencarbonate (3g)
Acetic acid (0.80 M)
125 mL Erlenmeyer flask
Beral pipette
Wood splints
Matches and a candle
baking soda
vinegar
small jar
medicine dropper
toothpicks
Procedure
1.
Measure approximately 3 grams (1/2 tsp.) of sodium
hydrogencarbonate and place it in the flask.
2. Using the pipette, add a few drops of acetic acid to the
sodium hydrogencarbonate. Gas bubbles will be formed.
3. Light a wooden splint or toothpick from the candle.
4. Carefully tip the flask and insert the burning splint
into the neck of the flask and observe the effect of the
gas (carbon dioxide) upon the flame.
5. Using the candle, relight the splint and test the gas
again.
Questions
1. Write the equation for the reaction occurring in the
above experiment.
2. Describe the effect of carbon dioxide on the burning
splint?
3. What property of carbon dioxide allowed us not to us a
stopper or lid?
4. Sine carbon dioxide is often used in fire extinguishers;
describe how you could use this experiment to create your
own extinguisher.
5. Other chemicals can react to produce carbon dioxide.
Compare this reaction with the one used in Experiment 5
of this book.
Countertop Chemistry
The Science House, NC State University
27
Experiment #9
Teacher's Notes
1. The equation for this reaction is:
NaHCO3 (s) + HC2H3O2 (aq)
---> NaC2H3O2 (aq)
+ CO2 (g)
+ H2O(l)
2. Carbon dioxide does not support combustion. Oxygen is
the substance that is necessary for any burning to take
place. The splint should be extinguished.
3. The density of carbon dioxide is 1.56 g/mL while that of
air is 1.0 g/mL. Since the carbon dioxide is denser than
air, it will remain below the air in the container.
4. For the extinguisher, use a plastic drink bottle. Drill
a small hole in the screw top, and insert a drinking
straw. Place a small amount of baking soda in the bottom
of a plastic drink bottle. Add to the container a small
container of vinegar. To initiate the extinguisher, tip
the bottle to start the reaction, and the carbon dioxide
will be formed.
Safety Precautions
1. Proper ventilation is required due to the odors of
vinegar.
2. The reaction containers should be wrapped with tape.
Pressure will increase if the containers are sealed.
Disposal
The solutions can be poured down the sink with subsequent
flushing with water. Unreacted sodium hydrogencarbonate
may be dissolved in water and poured down the sink.
Solid residues may be placed in the trash can.
Countertop Chemistry
The Science House, NC State University
28
Experiment #10
Single Replacement Reactions
This procedure will allow the student to develop a basic
activity series through an exploration of single
replacement reactions.
Materials









Substitutions
Zinc
Copper
Aluminum foil
0.1 M CuSO4
0.1 M AgNO3
0.1 M ZnSO4
1 M HCl
8 watch glasses
8 pipettes
galvanized nail
copper wire
spot plate
Procedure
1. After numbering a spot plate or 8 watch glasses,
arrange the solids
(using the tip of a spatula) in the respective wells as
show
on the diagram below:
I.
II.
Zn(s)
CuSO4 (aq)
II I.
(aq)
IV.
Zn(s)
AgNO3 (aq)
Cu(s)
AgNO3 (aq)
VI
V.
Zn(s)
Pb(NO3 )2
(aq)
V I I.
Zn(s)
HCl (aq)
Countertop Chemistry
Al(s)
CuSO4
. (s)
Cu
Pb(NO3 )2
(aq)
VIII
.Al (s)
HCl
(aq)
The Science House, NC State University
29
Experiment #10
2. Add approximately 10 drops of each required
solution.
3. Record any color changes or gas production in the
Data section.
4. Write a balanced equation for any reactions that
occur.
Include physical state symbols for the reactants and
products.
5. Construct an activity series by listing the elements
in decreasing order of reactivity. [e.g. Zn (s)+
Cu2+(aq) ----> Cu (s) + Zn2+ (aq) implies that zinc
is above copper in the activity series.]
Data and Observations
I. _______________________________________
_______________________________________
II. _______________________________________
_______________________________________
III. _______________________________________
_______________________________________
IV. _______________________________________
_______________________________________
V. _______________________________________
_______________________________________
VI. _______________________________________
_______________________________________
VII. _______________________________________
_______________________________________
VIII. _______________________________________
_______________________________________
Countertop Chemistry
The Science House, NC State University
30
Experiment #10
Teacher’s Notes
Anticipated reactions are:
I.
(aq)
Zn (s)
+ CuSO4 (aq)
--------> Cu (s)
+ ZnSO4
Copper forms on zinc; solution color becomes less blue
II.
2Al (s)
Al2(SO4)3 (aq)
III.
Zn (s)
+ 3CuSO4 (aq) --------> 3Cu (s) +
Copper forms onto aluminum.
+ 2AgNO3 (aq)
---------> 2Ag (s)
+ ZnSO4
(aq)
Silver crystals form on zinc solid.
IV.
Cu (s)
Cu(NO3)2 (aq)
solid.
+ 2AgNO3 (aq) --------> 2Ag (s) +
Silver crystals grow on copper
V.
Zn (s)
Zn(NO3)2 (aq)
of zinc.
+ Pb(NO3)2 (aq) ---------> Pb (s) +
Dull gray lead forms on pieces
VI.
VII.
Cu (s)
Zn (s)
(g)
is released.
+ Pb(NO3)2 (aq) ---------> No Reaction.
Copper will not replace lead.
+ 2HCl (aq) ---------> ZnCl2 (aq) + H2
Zinc reacts with acid and hydrogen gas
VIII.
2Al (s)
3H2 (g)
gas is released.
+ 6HCl (aq) ---------> 2AlCl3 (aq) +
Aluminum reacts with acid and hydrogen
Activity series that is achievable by the reactions in THIS
experiment:
1. Zn (Al)
2. Pb (Al)
4. Cu
3. H
5. Ag
Note that the position of aluminum in this series cannot be
determined exactly. It is MORE ACTIVE than Hydrogen.
Disposal
Aqueous solutions of HCl, Zn(NO3)2, AgNO3, and
Cu(SO4)2 may be flushed down the sink. Solutions of
Pb(NO3)2 should be evaporated and the solid residue
Countertop Chemistry
The Science House, NC State University
31
Experiment #10
placed in a solid waste disposal container. Solid
metals should also be placed in a solid waste
container.
Countertop Chemistry
The Science House, NC State University
32
Experiment #11
Double Replacement Reactions
This experiment demonstrates reactions that occur between
two aqueous solutions. The driving force for the reaction
is the formation of an insoluble product.
Materials







Substitutions
0.1 M NaCl
0.1 M CuSO4
0.1 M AgNO3
0.1 M Na3PO4
0.1 M NaOH
Spot plate
Droppers (5)
watch glasses (6)
I
II
NaCl (aq)
CuSO4 (aq)
NaOH (aq)
CuSO4 (aq)
IV
NaCl (aq)
AgNO3 (aq)
V
NaOH (aq)
AgNO 3 (aq)
III
Na3PO4 (aq)
CuSO 4 (aq)
VI
PO
Na3 4 (aq)
AgNO 3 (aq)
Procedure
1. Number wells 1-6. Place 10 drops of NaCl solution in
wells I and IV, 10 drops of NaOH in wells II and V,
and 10 drops of Na3PO4 in wells III and VI.
2. Using the diagram above, add 10 drops of CuSO4 to
wells I, II, and III and 10 drops of AgNO3 to wells
IV, V, and VI.
3. Note any color changes or precipitate formation in
the Data section.
4. Write a balanced equation for the reactions that
occur. Include physical state symbols for the
reactants and products. If no precipitate occurred,
NO REACTION occurred.
Countertop Chemistry
The Science House, NC State University
33
Experiment #11
Data and Observations
Well
I.
Well
II.
Well
III.
Well
IV.
Well
V.
Well
VI.
Countertop Chemistry
The Science House, NC State University
34
Experiment #11
Teacher's Notes
I.
NaCl (aq)
II.
(s)
2NaOH (aq)
III.
+ CuSO4 (aq)
+
Na3PO4 (aq)
-------> No Reaction.
CuSO4 (aq) ------->
+ CuSO4 (aq)
Na2SO4 (aq)
------->
No Reaction
IV.
NaCl (aq)
+
AgNO3 (aq)
V.
NaOH (aq)
+
AgNO3 (aq) ------->
NaNO3 (aq)
Na3PO4 (aq) +
AgNO3 (aq) ------->
2NaNO3 (aq)
VI.
(s)
------->
+ Cu(OH)2
NaNO3 (aq)
+ AgCl (s)
+ AgOH (s)
+ Ag3PO4
Disposal
All solids should be collected into a labeled waste
solid container. Aqueous solutions can be flushed
down the drain in the quantities suggested here.
Countertop Chemistry
The Science House, NC State University
35
Experiment #12
Gas Producing Reactions
Many types of chemical reactions produce gaseous
substances. These types of reactions may be classified as:
single displacement or double displacement. In this
experiment, you will investigate these types of reactions.
Materials

3 M HCL

Na2CO3

Small pieces of zinc

CaCO3

Spot plate
Small pieces of
magnesium
 Dropper

I.
Zn (s)
HCl (aq)
II.
Mg (s)
HCl (aq)
III.
Na2CO 3 (s)
HCl (aq)
IV.
CaCO 3(s)
HCl (aq)
Procedure
1. Place a piece of each solid (Zn or Mg ) or a small
amount of granular solid (using the tip of a spatula)
in the wells of a spot plate—as indicated on the
diagram.
2. Add 10 drops of 3 M HCl to each of the four wells.
3. Note any bubbling or fizzing indicating the production
of a gas in the Data section.
4. Write a balanced equation for the reactions that
occur. Include physical state symbols for the
reactants and products.
5. There are two different gases produced in this set of
reactions. What are the gases? What tests could you
perform to verify your hypotheses?
Countertop Chemistry
The Science House, NC State University
36
Experiment #12
Data and Observations
I. ________________________________________________
Identity of gas produced:_____________________________
II. _______________________________________________
Identity of gas produced:_____________________________
III. _______________________________________________
Identity of gas produced:_____________________________
IV._______________________________________________
Identity of gas produced:_____________________________
What are the tests that will verify the identity of
these gases?
Countertop Chemistry
The Science House, NC State University
37
Experiment #12
Teacher’s Notes
I.
Zn (s)
+ 2HCl (aq)
---------> ZnCl2 (aq)
+ H2 (g)
II.
Mg (s)
+ 2HCl (aq)
---------> MgCl2 (aq)
+ H2 (g)
III.
+ CO2 (g)
(l)
Na2CO3 (s)
IV.
CaCO3 (s)
+ CO2 (g)
+ 2HCl (aq)
+ 2HCl (aq)
--------> 2NaCl (aq)
--------->
CaCl2 (aq)
+ H2O (l)
+
H 2O
Test for:
H2(g):
CO2(g):
A burning splint will pop in the
presence of hydrogen. Hydrogen is
explosive. Remember the Hindenburg?
Experiment 8.
See
A burning splint will be extinguished
in the presence of carbon dioxide. See
Experiment 9.
Disposal:
Solids should be placed in solid waste containers.
Aqueous solutions can
be poured down the drain with added water.
Countertop Chemistry
The Science House, NC State University
38
Experiment #13
Red, White, and Blue I
Demonstration
This colorful demonstration displays chemical reactions
that can be performed with common substances.
Materials



Substitutions
Phenolphthalein solution
Aluminum foil
Magnesium sulfate heptahydrate
6M ammonia
3-250 mL beakers
plastic cups
 Glass stirring rod


Epsom salt
household ammonia
3 clear
Copper sulfate pentahydrate
Killer K-77
 Water

plastic straw
Roebic Root
Procedure
1. Put 5 drops of phenolphthalein solution in the first
beaker. This should be done shortly before the
demonstration, since it will evaporate quickly.
2. Dissolve 5 crystals of magnesium sulfate heptahydrate
and a little bit of water (3-5 mL) in the second
beaker.
3. Dissolve three small (pea-sized) copper sulfate
crystals in a small amount of water (3-5 mL) in the
third beaker.
4. Wrap the cups with aluminum foil to enhance the
curiosity of the audience.
5. Pour the ammonia solution into each cup—using a volume
that will render the solution invisible to the
audience.
6. Lift the aluminum foil masks to reveal the red, white,
and blue colors.
Countertop Chemistry
The Science House, NC State University
39
Experiment #13
Teacher's Notes
1. The "red" coloration is due to the presence of an
indicator, phenolphthalein, in a base, ammonia.
2. The "white" coloration is due to a precipitate, which
forms when MgSO4 reacts with aqueous NH3. Mg(OH)2 is
the insoluble white product.
3. The "blue" coloration is due to a complex ion that
forms when Cu2+ ions react with aqueous ammonia. The
formula for the complex ion is Cu(NH3)4 2+
4. The phenolphthalein solution should be placed in the
cup or glass JUST BEFORE performing the demonstration.
The indicator is a tincture (a solution of the solid
in alcohol) and will evaporate rapidly. After it
evaporates, the "trick" will not work.
Countertop Chemistry
The Science House, NC State University
40
Experiment #14
Rate of Solution - Demonstration
Several factors can increase the rate of dissolutions for a
solid. In this demonstration, you will investigate some of
these factors.
Materials










Substitutions
3-600 mL beakers
3-1 quart jars
Stirring rod
spoon
Mortar and pestle
cup and spoon
Large hot plate
warming tray with 2 burners
1-800 mL beaker
sauce pan
2-400 mL beakers
2 measuring cups
3 sugar cubes (sucrose)
Balance
Club soda (small bottle)
Vacuum pump with bell jar attached
Procedure
1. Into the three 600 mL beakers (labeled 1, 2, 3), add the
following:
Beaker
1
2
3
Contents
300 mL of hot H2O (about 80 oC)
300 mL of cold H2O (about 20
oC)
300 mL of cold H2O (about 20
oC)
2. Use a mortar and pestle or the back of a spoon to crush a
sugar cube.
3. Drop into beaker 1: one sugar cube; into beaker 2 one sugar
cube; into beaker 3, add the crushed sugar from step 2.
4. Using the stirring rod, stir the contents of beaker 2,
leaving beakers 1 and 3 unstirred.
5. Observe what happens. Which method increased the rate at
which sugar dissolved most? Record your data below. Draw
some conclusions based on your observations.
Data and Observations
Countertop Chemistry
The Science House, NC State University
41
Experiment #14
Rate of Solution for sugar cubes in water – 1st, 2nd, and 3rd
Beaker
1
2
3
Contents
300 mL of hot H2O
300 mL of cold H2O
300 mL of cold H2O
Order of dissolving
Questions
1. How does crushing the solute (sugar) increase the rate
of solution?
2. Suppose you had a cube (6 sides) that measured 20 cm x
20 cm on each face.
How much surface area would be
exposed to the solvent?
3. What surface area would result if the same cube was
crushed into 8 cubes with each face measuring 10 cm x
10 cm?
4. How much area would be exposed if the cubes were
crushed further into 8,000 cubes with each face
measuring 1 cm x 1 cm?
5. Why does stirring aid the solution process?
6. What was the effect of increasing the temperature of
the water? Why?
Countertop Chemistry
The Science House, NC State University
42
Experiment #14
Extension
1. Carefully open the small bottle of club soda. Do not
shake the bottle prior to opening it. Pour equal amounts
into the two 400 mL beakers or measuring cups. Quickly,
take the mass of each beaker and record those masses in
the Data section.
2. Place one beaker of soda on the hot plate. As the soda
heats, what do you observe? Take the second beaker of
soda and place it under the bell jar of the vacuum pump.
Turn the vacuum pump on. What happens? Is the solution
boiling? When the bubbling stops , remove the beaker
from the hot plate, let it cool to room temperature
(about 5-10 minutes) and reweigh it. Remove the beaker
from the bell jar and weigh it. Record the masses below.
What was the change in mass?
a.
Mass of soda in vacuum pump: Before ________g
After
________g
Difference ________g
b.
Mass of soda from hot plate: Before ________g
After
________g
Difference ________g
3. What do these differences in mass tell you about the
solubility of a gas in a liquid?
a) Why should soft drinks be kept in the
refrigerator?
b) If you shake a bottle of soda pop before you
open it what will happen? Why?
Teacher's Notes
Prior to step 1, you may wish to divide the class into groups
of 3 students, with each student responsible for one of the
three beakers.
The greater the surface area of the solute, the faster the
rate of dissolution of the solute. Crushing increases the
amount of surface area exposed to the solvent.
1 face (20 cm x 20 cm) = 400 cm2
2400 cm2
Countertop Chemistry
1 cube (400 cm2 x 6 faces) =
The Science House, NC State University
43
Experiment #14
1 face (10 cm x 10 cm) = 100 cm2
faces)=4800 cm2
1 face (1 cm x 1 cm)= 1 cm2
8 cubes 8(100 cm2 x 6
1 cube (1 cm2 x 6)=6 cm2
8000 cubes=48,000 cm2
Stirring distributes the solute throughout the solution and
therefore increases the rate of dissolution. It may actually
break the solute up into smaller units therefore mirroring the
same effect as "crushing" the solute. Most students will
predict that heating the water is the single greatest way to
increase solution formation. Ask that the students indicate
the fastest technique for dissolution prior to the experiment.
They will be surprised to find that, provided the water is not
boiling, the sample in the heated water is the LAST to
dissolve. Apparently the convection created by the hot
solvent is not as effective as a larger surface area in
accelerating the dissolution. Point out that packets of sugar
and sugar substitutes are granulated and when stirred,
dissolve very easily in cold beverages.
Henry's Law states that the mass of a gas dissolved in a given
volume of liquid is directly proportional to the pressure of
the gas applied. Soft drinks are bottled at 10-15 times
atmospheric pressure to increase the concentration of CO2 in
solution. Soft drinks are NOT BOILING as the gas is released!
There are several grams of carbon dioxide in a small bottle of
club soda. Your students might want to estimate the amount of
gas they would consume with a 20 oz. soft drink--or the amount
that is in a 3-Liter cola!
Certainly, some of the mass lost
on the hot plate is due to evaporation. Some of the soda
(water) will also be lost while the soda is under vacuum—owing
to the reduction of vapor pressure of the solvent. You will
remember the caution “Do not shake the bottle of club soda
before opening it”. Shaking causes carbon dioxide to escape
from the solution and the pressure will increase above the
liquid, resulting in a premature release of the gas.
Safety Precautions
The hot plate should not be too hot! The water used with the
sugar cubes must not be boiling (approximately 80˚ C is a
reasonable temperature). Any glassware placed on the hotplate
should be heat resistant.
Disposal
All solutions may be poured down the sink.
Countertop Chemistry
The Science House, NC State University
44
Experiment #14
Countertop Chemistry
The Science House, NC State University
45
Experiment #15
Ice Cream
Adding a solute to a solvent lowers the freezing point of
that solvent. This change in freezing point is referred
to as a colligative property. In this experiment, you
will use the lowered freezing point of water to chill
another mixture (ice cream) to the solid state.
Materials

1 quart Ziploc™ bag



1 gallon Ziploc™ bag
1/2 cup milk
1/2 cup whipping cream
1/4 cup sugar
1/4 teaspoon vanilla
flavoring


Sodium chloride or rock
salt
 Ice
 Thermometer
 Measuring cups (1, 1/2,

and 1/4 c.)
 Plastic spoons
 Styrofoam™ cups
Procedure
1. In a quart Ziploc™ bag, place 1/4 cup sugar, 1/2 cup
milk, 1/2 cup whipping cream, and 1/4 teaspoon
vanilla flavoring. Seal the bag securely and mix
well.
2. Place 2 cups of ice into the gallon Ziploc™ bag.
3. Using the thermometer, measure and record the
temperature of the ice in the Data section.
4. Add 1/2 - 3/4 cup of sodium chloride to the gallon
bag.
5. Place the sealed quart bag into the gallon bag.
Close the large bag securely.
6. Holding the large bag by the top seal, gently rock
the bag from side to side. Do not hold the bag in
your hands—as it will be cold enough to cause tissue
damage to your hands.
7. Continue rocking the bag until the contents of the
quart bag have solidified (This should take 10-15
minutes).
Countertop Chemistry
The Science House, NC State University
46
Experiment #15
8. Measure the temperature of the salt/ice mixture in
the gallon bag and record the temperature.
9. Remove frozen contents from quart bag into
Styrofoam™ cups. Consume the contents of the cups.
Data and Observations
1.
2.
3.
Initial temperature of ice
_____
Final temperature of ice mixture
Change in temperature
_____
_____
Questions
1. Why is sodium chloride added to the ice?
2. Why are large crystals sodium chloride used instead
of small crystals?
3. Why is sodium chloride placed on icy patches on
highways and steps in the winter?
4. Why is sodium chloride used rather than sucrose?
Countertop Chemistry
The Science House, NC State University
47
Experiment #15
Teacher’s Notes
When a substance freezes, the particles arrange
themselves into an orderly pattern. This arrangement
is called a crystal. When sodium chloride is added to
the water, a solution is formed.
The forming of the solution interferes with the
orderly arranging of the particles in the crystal.
Therefore, more kinetic energy (heat) must be removed
from the solvent (water) for freezing to occur. This
results in a lower freezing point.
Furthermore, the more particles of solute (salt)
added, the more kinetic energy (heat) must be removed.
The greater the concentration of solute (salt), the
lower the freezing point of the solvent.
Answers to Questions
1.
Sodium chloride is added to the ice to lower the
freezing point of the ice.
2. Large crystals dissolve more slowly than small
crystals. This allows time for the ice cream to freeze
more evenly.
3. When sodium chloride is placed on the highway or
steps, the freezing point is lowered and the ice
melts.
4. Sodium chloride is used for three reasons; first, some
solids such as sugar do not dissolve in ice water as
well as salt, secondly, salt is an abundant mineral in
the form HALITE and is not expensive, and finally when
sodium chloride dissolves, it separated into two
particles (Na+ and Cl-), lowering the freezing point
further. Only advanced students would need to know
this concept. It is called ionic dissociation.
Credit: The formula for the ice cream mixture is due to Mr. William M.
Black, Kewanee High School, Kewanee, IL.
Disposal
The ice/salt mixture can be poured down the sink.
Ziploc™ bags can be washed and reused.
Countertop Chemistry
The Science House, NC State University
48
Experiment #16
Daffy Densities
All materials have characteristic densities. As long as
the materials do not mix or react, the less dense materials
will float on top of the more dense layers. This activity
can be done as a lab or demonstration and uses 4 solids and
6 liquids to create a colorful column.
Materials
Substitutions
Graduated cylinder
(cylindrical)
 Ethanol
(green)
 Dawn™ dishwashing detergent
detergent
 Dark corn syrup
 Vegetable oil
 Glycerin
 Water
 Food coloring (red and green)

OPTIONAL SOLIDS:
 Cork stopper
 Solid rubber stopper
 1 small piece of lead
 1 small block of oak wood
large vase
rubbing alcohol
liquid dishwashing
fishing cork bobber
rubber SUPERBALL
a lead sinker
Procedure
Before you begin, add red food coloring to the water and
green food coloring to the rubbing alcohol.
1. In order, slowly pour the following liquids into
a graduated cylinder:
a) Dark Karo syrup (pour without touching
the container sides)
b) Glycerin
c) Dawn dishwashing liquid (blue)
d) Water (with red food coloring added)
e) Vegetable oil (yellow)
f) Rubbing alcohol (with green food coloring
added)
2. Add small samples of the solids listed above, in
the order: a) lead, b) rubber, c) oak, and d) cork.
Try to avoid mixing the layers.
Countertop Chemistry
The Science House, NC State University
49
Experiment #16
Teacher's Notes
1. Other solids may be added and their relative densities
determined. Suggested solids include: A new penny
(made after 1986), candle wax, a wooden toothpick, a
small block of pine, and an ice cube
2. Students can complete this as a laboratory exercise.
If given some densities as 'knowns', then they should
be able to set approximate ranges for the other
materials.
Disposal
All liquids can be poured down the sink. Solids may be
reused.
Countertop Chemistry
The Science House, NC State University
50
Experiment #17
Red, White, and Blue II - Demonstration
This colorful demonstration illustrates the rule "likes
dissolve likes" by combining three immiscible liquids to
create a density column.
Materials
Substitutions
Blue lamp oil
Whole milk
Light corn syrup
Red food coloring
Tall form 400 mL beaker
glass jar





red lamp oil
blue food coloring
tall plastic or
Procedure
1. Wrap the outside of the beaker loosely with aluminum
foil so that you can pour your liquids into the glass
and can uncover the glass easily by removing the foil.
2. Add several drops of red food coloring to the light
corn syrup and invert several times to mix. (If you
are using red lamp oil, substitute blue food
coloring.)
3. Slowly pour the three liquids into the glass in the
order: a) red colored syrup, b) milk, and c) blue lamp
oil. The more slowly you are able to pour the liquids,
the less mixing that occurs.
4. Ask the students what color will result from mixing
red, white, and blue. Then lift the aluminum foil mask
to reveal three layers, with the red syrup on the
bottom, white milk over the syrup, and blue lamp oil
on top.
Teacher's Notes
Countertop Chemistry
The Science House, NC State University
51
Experiment #17
Because the milk is not exposed to air, the density
column will be stable for several days. The oil will
retard spoilage of the milk.
Most discount stores will carry colored lamp oil. The
colors available often depend on the season. You can
color your syrup differently to adjust for the color of
the lamp oil that is available.
The order of mixing isn’t crucial. To obtain maximum
separation of the layers you should pour the liquids in
the order suggested. There are two points to consider:
a. The relative densities of the liquids determine
the order of liquids in the column, with the
least dense liquid on the top, the most dense on
the bottom.
b. The polarities of the liquids prevent mixing. The
oil and syrup will be relatively non-polar, while
the milk is relatively polar.
Disposal
All substances can go down the drain with copious
amounts of water for disposal.
Countertop Chemistry
The Science House, NC State University
52
Experiment #18
Oobleck
Many of the materials we use every day, like starch, are
made up of molecules called Polymers. Poly means "many"
and mer means "unit." Because the units of chains are so
long, their movement is restricted.
Viscosity is a physical property of liquids that describes
their rate of flow. Honey and corn syrup are described as
having high viscosities because they flow more slowly than
water.
Materials






Substitutions
1 500 mL beaker
Spatula
1 aluminum pie pan
Scissors
Water
Cornstarch ( 1/2 box)
1 bowl
spoon
Procedure
1.
Pour 1 cup of cornstarch into a bowl or beaker.
2. Continue to add a small amount of water until the
solution begins to thicken. Stir carefully! Don't
fight the viscosity of the polymer.
3. Pour some of the polymer into the pie pan. Try to cut
it as you pour. Tap the polymer in the pie pan with
your hands. Pour some of the polymer into your hands
and roll it into a ball. Does the ball retain its
shape? Form a long rope (snake) with the polymer and
pull it apart quickly. What happens? With your
spoon, attempt to draw in the polymer. Can you write
your name?
Countertop Chemistry
The Science House, NC State University
53
Experiment #18
Extension:
Try making one of the other non-Newtonian fluids in this
lab manual. See Experiments 19 and 20.
Teacher's Notes
1. The Oobleck is a non-Newtonian fluid. A nonNewtonian fluid has properties of both a solid and a
liquid and reacts to stress with increased viscosity.
2. Oobleck can make a mess!! Be prepared for your
students to have some "play" time. Plenty of paper
towels and water should be on-hand.
3. If you are doing this for elementary age students,
you may want to add a drop or two of food coloring.
Then you can read Dr. Seuss' "Bartholomew and the
Oobleck".
4. The mixture of cornstarch and water can be considered
a colloidal suspension. A colloidal suspension is a
two-phase system in which the starch is not fully
dissolved in water but simply mixed into a permanent
suspension that will not settle upon standing.
5. Other examples of colloids are: fog, whipped cream,
foams, Jell-O, and styling gels.
Disposal
Oobleck can be spread onto a cookie sheet, dehydrated,
and the starch reused!!
Countertop Chemistry
The Science House, NC State University
54
Experiment #19
Gluep
Many of the materials we use every day, like starch, are
made up of molecules called polymers. Poly means "many"
and mer means "unit." Because the units of chains are so
long, movement is restricted.
Viscosity is a physical property of liquids that describes
their rate of flow. Honey and corn syrup are described as
having high viscosities because they flow more slowly than
water.
Materials
Substitutions
2-400 mL beakers
cups
 Elmer's Glue All
 Spatula
 25 mL graduated cylinder
 Borax
 Water
 Food coloring

2
jars or 2 Styrofoam™
spoon
measuring spoons
Procedure
1.
Mix 30 mL (2 tbsp.) of glue with 20 mL water (4
tsp.) in a beaker.
2.
Add 2 or 3 drops of your choice of food coloring.
3.
To the second beaker add 200 mL (3/4 cup) of water.
Add 2.6 grams (1/2 tsp.) of powdered borax and stir
until the borax dissolves.
4.
Add 15 mL (1 tbsp.) of the borax solution into
the beaker with glue and water.
5.
Stir gently allowing it to sit momentarily.
6.
Take the Gluep out of the beaker and stretch it.
Will it bounce?
Does the consistency change?
Can
you break it?
Countertop Chemistry
The Science House, NC State University
55
Experiment #19
Extensions
Try making one of the other non-Newtonian fluids in this
lab manual. See Experiments 18 and 20.
Teacher's Notes
1. Gluep is a non-Newtonian fluid--so-called because
of its unusual viscosities. A non-Newtonian fluid
has properties of both a solid and a liquid, and
reacts to stress with increased viscosity.
2. Glue can make a mess!! Be prepared for your
students to have
some "play" time. Towels and water should be onhand as bits of
“Gluep” will be on countertops.
3.
Caution students not to eat the glue or Gluep.
4. Alternative procedure: Replace the 400 mL beaker in
step 1 with a Styrofoam™ cup. Then in step 4, pour
the 15 mL of the borax solution into the cup
containing the glue/water mixture. This procedure
reduces cleanup time.
5.
The Elmer’s glue is a solution of a polymer. With
the addition of borax, the polymer chains become
cross-linked. In this type of reaction, the chains
are bonded together to create a larger, stronger
polymer.
Disposal
If you have Ziploc™ bags, you could allow the students
to take their Gluep home with them. Solutions of borax
can be poured into the sinks. Unused mixtures of the
borax and glue should be placed into a solid waste
container.
Countertop Chemistry
The Science House, NC State University
56
Experiment #20
Clear Slime Polymer
Many of the materials we use every day, like starch, are
made up of molecules called polymers. Poly means "many"
and mer means "unit." Because the units of chains are so
long, their movement is restricted.
Materials










Substitutions
2.46 g sodium borate
1 teaspoon of borax
0.63 g guar gum (1/4 tsp.)
200 mL water
5/6 cup of water
100 mL graduated cylinder
measuring cup
2-250 mL beakers
2-9oz plastic cups
2 stirring rods
2 spoons
Balance
Paper towels
Food coloring
4-5 Ziploc™ bags (1 per person)
Procedure
1. Pour 100 mL of water into a beaker.
2. Add the sodium borate to the water and stir until the
solid is completely dissolved (about 1 minute).
3. Label the solution.
4. Pour 80 mL of water into the other beaker
5. Add guar gum to water WHILE STIRRING. Continue
stirring until the solid is completely dissolved
(about 1 minute).
6. Label the solution.
7. Add food coloring of your choice to guar gum solution
and stir for 1 minute.
8. Add 5 mL of the sodium borate solution to the guar
gum solution. Stir for 1 minute then let it sit for
2 minutes.
Countertop Chemistry
The Science House, NC State University
57
Experiment #20
Extensions
1. Challenge students to modify the basic recipe and
demonstrate each resulting product. Can they create
a slime that is stretchy, or one that bounces?
2. Extend the activity into other disciplines by having
each team name their new product and create a
marketing strategy including packaging, cost
analysis, and advertising.
Teacher's Notes
The secret to this colloidal suspension is the guar
gum. It is not available through common sources and
must be ordered through a chemical company.
This slime can be stored in a Ziploc™ bag so students
can take it with them. It’s usual properties will
diminish over time as it dries out.
Try the other non-Newtonian fluids in this lab manual!
This recipe was adapted from a Flinn Scientific
publication and an issue of NSTA Science Scope
magazine.
Countertop Chemistry
The Science House, NC State University
58
Experiment #21
THE CAT'S MEOW
This activity is used to arouse interest in a common
substance, milk. Students are asked to form a hypothesis
about the behavior of milk as it is acted on by a household
detergent.
Materials
Substitutions
Large glass Petri dish
aluminum pie pan
Toothpick
wooden splint
Liquid dish detergent
laundry
detergent (liquid)
 Milk
 Food coloring - 4 different colors



Procedure
1. Pour milk into an aluminum pie pan to a depth of 1 cm
(1/2 inch).
2. Add a couple of drops of each of the food colorings
near the edge of the container. Arrange the drops so
that they are in positions equivalent to 3, 6, 9, and
12 o' clock
3. Dip the tip of a toothpick in detergent. Touch the
surface of the milk in the center of the pie pan and
hold the toothpick in place for a while. What
happens?
4. Experiment with the milk and toothpick. How is it
possible that the fairly quiet pan of milk is now
exhibiting such activity? Suggest a hypothesis that
may explain the phenomena that you observe.
Countertop Chemistry
The Science House, NC State University
59
Experiment #21
Extensions
If the milk is diluted with water, will the phenomena
still occur? Would this take place if low fat milk
were used?
Teacher's Notes
1. The most important aspect of this activity are the
observations, hypotheses, and conclusions that the
students draw. Whether or not they come up with the
right answer is not important. Although the phenomena
appear to be related to the detergent action on the
milk, it has not been proven what causes this activity
to occur.
2. Milk is a colloid. It contains not only salts and
sugars dissolved in water, but also small globules of
fatty substances and protein, which vary in diameter.
The fat globules, being hydrophobic, cannot dissolve
in the water. They can, however, dissolve in each
other.
Average Composition of Milk
Water
87 %
Total solids
13 %
Proteins (casein)
3-4 %
Lipids (triglycerides)
3.5-5 %
Sugars (lactose)
4.5-5 %
3. Detergents have a hydrophilic and hydrophobic end in its
molecular structure. This structure reduces the surface
tension of water.
4. The detergent tries to surround the fat in the milk but
the fat is so evenly dispersed that is simply turns over
and over. This causes the swirling effect that we
notice.
Countertop Chemistry
The Science House, NC State University
60
Experiment #21
Disposal
All solutions can be poured down the sink.
Countertop Chemistry
The Science House, NC State University
61
Experiment #22
Cabbage Juice Indicator
Chemists use indicators to test whether a substance is an
acid or a base. Indicators work by turning a distinctive
color in the presence of an acid or a base. You can make
your own indicator from red cabbage. You can also make
indicators from the juice of elderberries, blackberries,
radish skins, apple skins, or cherries.
Materials









Substitutions
Hot plate
head red cabbage
Food processor
1000 mL beaker
500 mL beaker
4-5 250 mL beakers
Sieve
Test substances**
Distilled water
knife and cutting board
large size saucepan
large jar
4-5 small jars
tea strainer or colander
** Recommend materials: baking soda, bathroom cleaner (e.g.
Formula 409), washing soda, vinegar, lemon juice, milk,
cream of tartar, orange juice, milk of magnesia, lime, soft
drinks, or ammonia)
Procedure
1.
Chop red cabbage finely.
saucepan.
Boil a pint of water in a
2. Add the red cabbage carefully to the boiling water and
take the saucepan off the heat. Let it stand for 30
minutes until it is completely cool.
3. Using the sieve, strain the liquid into a jar and
throw away the used cabbage. The liquid should be a
dark reddish purple color. Add alcohol to reduce the
spoilage of the indicator. Use a 1 to 5 ratio of
alcohol to volume of water.
4. The color will change as you add acids or bases. To
test a substance, pour a little of your substance into
a small jar. Then add a drop or two of the cabbage
juice indicator. A change in color indicates its
acidity or alkalinity.
Countertop Chemistry
The Science House, NC State University
62
Experiment #22
COLORS OF RED CABBAGE JUICE AT DIFFERENT PH VALUES
Color Red
Rose
pH 1 2 3 4
ACID
Purple Blue
5 6 7 8
Neutral
9
Green
yellow
10 11 12 13 14
BASE
Data and Observations
Substance
Color
Approximate pH
Acid or Base
Lemon
juice
Lime
Washing
soda
Ammonia
Cream of
tartar
Muriatic
acid
Bathroom
cleaner
Vinegar
Baking
soda
Soft drink
Countertop Chemistry
The Science House, NC State University
63
Experiment #22
Extensions
Soak some filter paper in the cabbage juice indicator.
Allow the paper to dry, then cut it into strips.
Conduct an "at home" pH test of other household items.
Tape your strips to a piece of notebook paper and
bring them back to class. Compile your results. What
can you say about household cleaners? Where are most
household acids found?
Teacher's Notes
1. Lemons, vinegar, cream of tartar (potassium acid
tartrate), orange juice, and sour milk will be acidic
solutions.
2. Pure distilled water is the only substance listed
that should be neutral.
3. Tap water may be slightly acidic—owing to dissolved
carbon dioxide. Baking soda is also a weak base.
4. The strong bases will be bathroom cleaners, ammonia,
washing soda, milk of magnesia, and lime.
5. The indicator can be frozen in ice trays and saved
for later use. The indicator mixed with alcohol will
last for months! The strips can also be refrigerated
and will last for months as well.
* Canned cabbage may be used as an alternate source of
cabbage juice.
Disposal
All solutions can be poured down the sink. Solid bits
of cabbage should be put into a solid waste container
and emptied at the end of the school day. (Cabbage
will begin to smell very badly if left overnight.)
Countertop Chemistry
The Science House, NC State University
64
Experiment #23
Invisible Ink - Demonstration
This demonstration shows that phenolphthalein is a chemical
that displays different colors depending on the acidity and
the alkalinity of the environment.
Materials
Substitutions
Phenolphthalein solution
Cotton swab
brush
 White typing paper
towels
 1-100 mL beaker
 Rubbing alcohol
 Ammonia
ammonia
 Acetic acid


artist's paint
roll of paper
glass or plastic cup
Windex spray with
vinegar
Procedure
1. Before performing your demonstration roll out one
sheet of paper towel. Dip the swab in the
phenolphthalein solution and use it to write a message
or draw a picture on the paper towel. Prepare two
additional sheets in the same manner. Let them dry in
the air. Roll the paper towel back.
2. In front of the audience roll out the paper towel and
spray with ammonia or Windex. A message appears in
pink ink.
3. Spray the second paper towel with Windex (to which
you’ve added acetic acid). Nothing will happen.
Spray the third paper towel with Windex (with ammonia)
and it works again. Ask the students to explain what
happened!
Countertop Chemistry
The Science House, NC State University
65
Experiment #23
Teacher's Notes
1. Phenolphthalein is an indicator that is colorless in
the presence of an acid. It will turn bright pink
in the presence of a base, like ammonia.
2. The same "secret message" sheets may be used
repeatedly, if multiple performances are required.
I usually tape the tops and bottom of the sheets to
a wall or surface that Windex will not harm.
3. You may wish to “spray” the sheets with the “pink
message” with CO2 gas.
4. This gas may be obtained by capturing the gas as dry
ice sublimes. Alternatively you may make CO2 gas by
pouring some acetic acid onto sodium hydrogen
carbonate which you’ve placed into a plastic soda
bottle.
Disposal
Paper towels should be disposed of in a solid waste
container. Solutions of acetic acid and ammonia can be
stored in suitable containers in the stockroom.
Countertop Chemistry
The Science House, NC State University
66
Experiment #24
The Witches' Potion - Demonstration
This demonstration shows that phenolphthalein is an
acid/base indicator.
Materials
Substitutions
2-500 mL beaker
containers
 4-250 mL beakers
 Phenolphthalein solution
 3 M ammonia (10%)
ammonia
 3 M acetic acid
 Water

2 large, clear
4 tall glasses
colorless household
vinegar
Procedure
1. Prepare four 250 mL beakers and label them 1-4. In
beakers 1 and 3, put 5 drops of phenolphthalein. In
beakers 2 and 4, put 5 drops of ammonia
*If you prepare these ahead of time, cover them to
reduce
evaporation.
2. In one of the large beakers put 20 drops of vinegar.
Fill the other large beaker with water.
3. Choose 5 volunteers: 4 witches and someone to read the
poem.
Read:
"Four witches made quite a commotion
When I invited them to create a potion.
Into four glasses went the magic brew,"
STOP
Fill each glass 1/4 - 1/2 full with water.
potions will be clear and colorless.
4.
All
Read: "And into a rage the first witch flew:
She shrieked, 'There's no magic in this drink
To cast a spell, it must be pink!'
The second witch laughed, "The pink is here!"
Pour your brew in--the color will appear!"
STOP
Countertop Chemistry
The Science House, NC State University
67
Experiment #24
Have Witch #1 pour her water into the glass of Witch
#2. The phenolphthalein will react with the ammonia
and turn bright pink, indicating the presence of a
base.
5.
Read: "The third witch shrieked, 'We need more!'
And gave her brew to Witch number four."
STOP
Have Witch #3 pour her water into the glass of Witch
#4. The phenolphthalein will react with the ammonia
and turn bright pink, indicating the presence of a
base.
6.
Read: "Now there are two glasses of pink,
But no one asked me what I think!
I'll invoke my powers to make it clear'Be Gone Pink!' 'Watch it disappear!!'"
END
Pour both glasses with the pink solutions into the
glass container with vinegar. The acid will
neutralize the base and the liquid will be colorless
again.
Countertop Chemistry
The Science House, NC State University
68
Experiment #24
Teacher's Notes
Phenolphthalein is an indicator that turns pink in the
presence of a base, but is colorless in an acid.
Because the phenolphthalein solution is made with
alcohol, it will evaporate easily. You should plan to
put the solutions in beakers just before the
demonstration to reduce evaporation.
Disposal
The solutions can be flushed down the drain.
Countertop Chemistry
The Science House, NC State University
69
Experiment #25
What’s in a Penny?*
The procedure will allow the students to use chemical
reactions to observe the composition of an alloy
Materials

Substitutions
Pennies minted after 1982
12 M (concentrated) hydrochloric acid
muriatic acid
 2-150 mL beakers & 400-mL beakers
small and large
jars
 6 M NaOH solution
 Elemental zinc, granulated
 Metal shears
 Hot plate
 Evaporating dish
 Tongs

Procedure
Percentages of Copper and Zinc in a Penny
1. Obtain a penny minted after 1982 and record the mint
date. Use metal shears to cut the edges of the coin in
several places.
2. Weigh the penny and record the mass.
3. Under the hood, place the penny into a 150-mL beaker
and add approximately 20 mL of concentrated
hydrochloric acid.
4. When the coin stops producing gas bubbles, decant the
acid into another 150-mL beaker. Record the reaction
time.
5. Wash the penny in distilled water. Then rinse with
acetone. When the penny is dry, weigh and record the
mass of the copper shell.
6. Calculate the percentages of copper and zinc in the
penny.
Countertop Chemistry
The Science House, NC State University
70
Experiment #25
Preparation of Brass Alloy
1. Place an evaporating dish under a hood, with
approximately 5 g of zinc and approximately 50 mL of
6 M sodium hydroxide. While the volumes are not
critical, assure that the zinc is covered with the
NaOH solution. With the hot plate, heat the mixture
to boiling. Carefully (with tongs), place the copper
shell into the mixture.
2. Leave the coin in the solution until it turns a
silver color (about 45 seconds).
3. Remove the coin (with tongs) and dip it into a beaker
of water to remove any remaining NaOH solution. Dry
the coin.
4. With the tongs, place the coin on the surface of the
hot plate (Be careful! It will be VERY HOT). Turn
the coin to heat evenly. A gold color will appear.
Do not overheat! The gold color will disappear if
the coin is overheated.
5. Dip the coin into a beaker of water and dry.
Data Section
Mint date of penny
Mass of penny
Mass of copper
Percentage of copper
Mass of zinc
Percentage of zinc
Questions
1. List two observations that give evidence of a
chemical reaction occurring between the zinc and the
hydrochloric acid.
2. What type of reaction is represented in question 1
(gas producing, precipitation, oxidation-reduction,
etc.)? Why?
3. Would the reaction of the penny with hydrochloric
acid have occurred if the penny had not been cut?
Countertop Chemistry
The Science House, NC State University
71
Experiment #25
Teacher's Notes
Pennies that have been made after 1982 are a composite of
zinc and copper. The copper is plated on top of the zinc.
What if we could reverse this composite by placing the
zinc on top of the copper? The zinc can be removed from
the penny by cutting the coin and creating a reaction
between the zinc and the concentrated hydrochloric acid:
Zn(s) + HCl(aq)

Zn2+(aq) + Cl - (aq) +
H2(g)
Copper does not react with hydrochloric acid. After
removing the zinc, reweigh the penny and obtain the
mass of copper that is present. The remaining copper
can be plated with zinc and the brass alloy produced.
This process entails first creating a reaction between
zinc and 6M of sodium hydroxide:
Zn(s) + 2 OH-(aq)

ZnO22-(aq) + H2 (g)
The zinc will adhere to the copper. Upon heating, a
brass alloy forms.
Answers to Questions
1.
Two observations: gas evolution; consumption of zinc
inside penny
2.
Type of reaction represented in question 1: gas
producing and oxidation-reduction.
3.
The reaction with HCl occurs only if the HCl contacts
the zinc.
Safety Precautions
1.
Proper eye protection should be used at all times.
2.
Handle hydrochloric acid and concentrated sodium
hydroxide with care! Gloves should be worn when
working with these chemicals
3.
Hydrogen gas, produced in Part A, is very reactive! Do
not have open flames or sparks near gas production or
storage area. Pressure will build up quickly inside
the flask or jar so the container should never be
tightly sealed. Explosions could occur from increased
pressure.
Disposal
Countertop Chemistry
The Science House, NC State University
72
Experiment #25
All aqueous solutions may be flushed down the sink with
copious amounts of water. Use care when disposing of
concentrated acid since it may spatter when poured into
the sink.
*This experiment is based upon similar ones from Hubert
Alyea described in “Tested Demonstrations.
Countertop Chemistry
The Science House, NC State University
73
Experiment # 26
Formulas Poker
Students can practice writing chemical formulas in a card
game.
Materials
Each deck should contain:
1. At least one card with each of the following
ions(47cards):
Ba+2
Be+2
Sr+2
Cu+2
Na+1
Mg+2
Sc+3
Cu+3
Ca+2
Ag+1
Al+3
Fe+2
Li+1
K+1
Hg+2
H+1
Pb+2
V+3
Sn+1
Fe +3
Zn+2
Ni+3
Rb+1
NO3-1
HCO3-1
NO2 -1
PO4 –3
SO4–2
HPO4-2
SO3 –2
NH4 +1
HSO4 -2
OH-1
CO3 -2
ClO4 -1
CrO4-1
S-2
Cl-1
O-2
AsO4-2
F-1
C2H3O2–1
N -3
H2PO4 -1
Br-1
I-1
P-3
2. One blank or FREE card
3. Fifteen cards: five with each of the following
subscripts: 1,2,3
Procedure
1. This game is played as a 5-card draw.
The dealer will
pass out 5 cards to each player from the shuffled deck,
placing all remaining cards in a central stack.
2. Each player may discard as many as 3 cards in one
rotation—taking as many cards from the central stack as
s/he discards.
Play begins with the player to the
right of the dealer.
Players try to make a chemical
formula that uses as many of their cards as possible.
If they cannot play, they must pass.
It is possible to
make two chemical formulas in one play.
Once a player
uses a number of cards to make a formula, that player
Countertop Chemistry
The Science House, NC State University
74
Experiment # 26
should draw, from the central stack, as many cards as
s/he used.
Play then passes to the player on the
right.
3. Total the score by the number of cards that a player is
able to use to make a chemical formula.
It is possible
for a player to score as many as 5 points per hand.
See Sample Score Sheet.
Each player has her/his own
score sheet.
4. Play continues until no more formulas can be made.
Countertop Chemistry
The Science House, NC State University
75
Experiment # 26
Score Card
TOTAL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Countertop Chemistry
The Science House, NC State University
76
Experiment # 26
1
(SAMPLE)
Score Card
Mg2+
NO3-1
2
-----
-----
3
2
Sc3+
ClO4-1
3
-----
-----
3
3
NH4+1
3
N-3
1
-----
4
4
V+3
2
S-2
3
-----
4
5
Na+1
Cl-1
Ca+2
NO3-1
2
5
TOTAL
6
7
8
9
10
11
12
13
14
15
16
17
18
Total
Countertop Chemistry
19
The Science House, NC State University
77
Experiment #27
Radioactive Decay of Candium
Radioactive decay processes occur in accordance with first
order kinetics. This simulation provides a simple example
of the rate at which a radioactive isotope decays.
Materials



M&M™ candy pieces
Re-sealable bag
Graph paper
Procedure
1. Place 50 atoms of candium (pieces of candy) in the bag.
2. Seal the bag and gently shake for 10 seconds.
3. Gently pour out candy.
4. Count the number of pieces with the print side up—and
record the data. These atoms have "decayed".
5. Return only the pieces with the print side down to the
bag. Reseal the bag.
6. Consume the "decayed atoms”.
7. Gently shake the sealed bag for 10 seconds.
8. Continue shaking, counting, and consuming until all the
atoms have decayed.
9. Graph the number of undecayed atoms vs. time.
Data and Observations
Half-life
Total Time
# of Undecayed Atoms
# of Decayed Atoms
0
1
2
3
4
5
6
7
8
Countertop Chemistry
The Science House, NC State University
78
Experiment #27
Questions
1. What is a half-life?
2. In the experiment, what was the half-life of the
element candium?
3. At the end of two half-lives, what fraction of the
atoms had not decayed?
4. Describe the shape of the curve drawn in step 9.
5. Repeat the experiment three more times, starting with
30 atoms, 80 atoms, and 100 atoms of candium. Compare
the resulting graphs.
6. Repeat the experiment using half-lives of 5 seconds, 20
seconds, and 1 minute. Compare the resulting graphs.
Countertop Chemistry
The Science House, NC State University
79
Experiment #27
Teacher's Notes
Some naturally occurring isotopes of elements are not
stable. They slowly decompose by discarding part of
the nucleus. The isotope is said to be radioactive.
This nuclear decomposition is called nuclear decay.
The length of time required for half of the isotope to
decay is the substance's half-life. Each radioactive
isotope has its own particular half-life. However,
when the amount of remaining isotope is plotted against
time, the resulting curve for every radioisotope has
the same general shape.
Hint:
Make sure you use candies with printing on
one side (plain M&Ms™).
Answers to Questions
1. Half-life is the length of time required for one half
of an isotope to decay.
2. The half-life of candium in this activity was 10
seconds.
3. At the end of two half-lives, 1/4 of the original
sample remained and 3/4 of the sample had decayed into
a new element.
4. The graph is a decreasing logarithmic curve.
5. The shape of the graphs will be almost the same.
6. The shape of the graphs will be almost the same.
Countertop Chemistry
The Science House, NC State University
80
Appendix
Comparison of Solutions, Suspensions, and Colloids
Type
Particle size
Permanence
Solution
< 1 nm
Permanent
Colloid
between 1 nm and 100
Permanent
nm
Suspension
> 100 nm
Settle out
Properties of Solutions, Colloids, & Suspensions
Solutions
Do not settle out
Colloids
Do not settle out
Suspensions
Settle out on standing
Pass unchanged through
Pass unchanged through
Separated by filter paper
filter paper
filter paper
Pass unchanged through
Separated by a membrane Separated by a membrane
a membrane
Do not scatter light
Scatter light
Affect colligative properties Do not affect colligative
properties
Scatter light
Do not affect colligative
properties
Handy conversions
1 ounce (avoirdupois) = 28.35 grams
1 ounce (liquid) = 29.58 milliliters (mL)
1 tablespoon (liquid) = approximately 10 milliliters (mL)
1 pound = 454 grams
Countertop Chemistry
The Science House, NC State University
81
Appendix
Chemicals Used in the Manual
(MSD Sheets Should be Present for these Materials)
Acetic acid (vinegar)
Lemon juice
Water
Aluminum foil
Light corn syrup
Whipping cream
Aqueous ammonia
Lime (CaO)
Windex™
Bathroom cleaner
M&M™ candies
Yeast
(Formula 409™)
Magnesium sulfate
Zinc (mossy)
Borax (Na2B4O7)
heptahydrate
Zinc sulfate
Calcium carbonate
Magnesium wire
Calcium chloride
Milk
Club soda
Milk of magnesia
Copper sulfate
(Mg(OH)2)
Copper wire or foil
Orange juice
Cornstarch
Pennies
Cream of tartar
Phenol red
(potassium acid
Phenolphthalein
tartrate)
solution (1%)
Dark corn syrup
red or blue lamp oil
Dawn™ dishwashing
Silver nitrate
detergent
Sodium carbonate
Dry ice (CO2)
Sodium hydrogen-
Elmer’s Glue All™
carbonate
Ethanol
Sodium hydroxide
Food coloring (red,
Sodium phosphate
green, and blue)
Soft drinks
Glycerin
Steel wool
Guar gum
Sucrose
Hydrochloric acid
Vanilla extract
Hydrogen peroxide
Vegetable oil
Ice
Washing soda
Lead nitrate
(Na2CO3)
Countertop Chemistry
The Science House, NC State University
82
Appendix
Chemicals Used in the Manual
(MSD Sheets should be present for these materials)
Chemicals found mainly in chemical supply houses:
Copper wire or foil
Silver nitrate
Guar gum
Sodium hydroxide
Lead nitrate
Sodium phosphate
Magnesium wire
Zinc (mossy)
Phenol red
Zinc sulfate
Phenolphthalein solution (1%)
Chemicals found in grocery/hardware/pool or agricultural supply stores:
Grocery
Acetic acid (vinegar)
Aluminum foil
Aqueous ammonia
Bathroom cleaner (Formula 409™)
Borax™
Cornstarch
Cream of tartar (potassium acid tartrate)
Dark corn syrup
Dawn™ dishwashing detergent
Dry ice
Elmer’s Glue All
Food coloring
Glycerin
Hydrogen peroxide
Ice
Lemon juice
Light corn syrup
M&M™ candies
Magnesium sulfate heptahydrate (epsom
salts)
Milk
Milk of magnesia
Orange juice
Red or blue lamp oil
Sodium carbonate (washing soda)
Sodium hydrogen carbonate
Soft drinks
Steel wool
Sucrose
Vanilla extract
Vegetable oil
Water
Whipping cream Windex™
Yeast
Calcium carbonate (chalk)
Calcium chloride
Copper sulfate
Ethanol (Everclear) ABC store
Lime (CaO)- agricultural supply
Hydrochloric acid (muriatic acid)
Hardware/Pool/Agricultural Supply
Countertop Chemistry
The Science House, NC State University
77
Appendix
Sites for obtaining Material Safety Data Sheets (MSDS)
Having a MSD Sheet for every chemical in your stockroom is a legal
requirement—not just a good idea. With that in mind, manufacturers ship MSD
sheets with all chemicals. However, a typical stockroom contains many older
chemicals that may not have arrived with an MSDS. Obtaining one is vital.
Below are some sites from which MSD sheets can be downloaded. Please note
that URLs frequently change. Below are listed sites that have been relatively
stable for some time. In the event that these sites have moved, enter “MSDS”
into a search engine (e.g. GOOGLE) to obtain updated URLs for MSDS sources.
1.
The National MSDS Repository
http://www.msdssearch.com/
2.
A regularly updated site with free resources for material safety data sheets
sites
http://www.ilpi.com/msds/
3.
The Physical and Theoretical Chemistry Laboratory Oxford University
Chemical and Other Safety Information
http://physchem.ox.ac.uk/MSDS/
4.
The MSDS HyperGlossary
http://www.ilpi.com/msds/ref/
Safety Software
The state of North Carolina provides science teachers a software package
“Teaching Science Safety” by Jack Gerlovich for public schools (in both Mac and
PC formats). Call the NC Department of Public Instruction (Secondary Science
Division) for information on obtaining a copy of the software. The package
contains valuable information on liabilities, many printable blank forms, safety
tips, a spreadsheet for your stockroom inventory, and more.
Countertop Chemistry
The Science House, NC State University
78
Appendix
COMPOUND
FORMULA
COMMERCIAL
EQUIVALENT
SOURCE
vinegar ( 5% )
grocery store
acetone
CH3COOH
CH3COCH3
acetone
hardware store
acetylsalicylic acid
C9H8O4
aspirin
drug store
aluminum
Al
foil or wire
grocery or hardware
store
aluminum potassium
sulfate
KAl(SO4)2
alum
drug store
aluminum sulfate
Al2(SO4)2
(NH4)2CO3
flocculating powder
pool supply store
smelling salt
drug store
NH4Cl
NH4 (aq)
sal ammoniac
drug store
ammonia cleaner (10%)
grocery store
NH4NO3
(C6H10O5)n
nitrate of ammonia
garden supply store
cornstarch
grocery store
vitamin C
drug store
boric acid
C6H8O6
H3BO3
boric acid eyewash
solid roach killer
drug store
hardware store
butane
C4H10
disposable lighter
grocery store
acetic acid
ammonium carbonate
ammonium chloride
ammonium hydroxide
ammonium nitrate
amylose
ascorbic acid
fluid
caffeine
calcium carbonate
calcium chloride
calcium hydroxide
calcium oxide
calcium phosphate,
C8H10N4O2
CaCO3
No-Doz™ tablets
drug store
white chalk,calcium
supplement
drug store
CaCl2
Ca(OH)2
"De-Ice" for sidewalks
grocery store
slaked lime, some
antacids
hardware store
pool supply store
CaO
Ca(H2PO4)2
Quicklime™
hardware store
superphosphate
garden supply store
CaSO4
plaster of paris
gypsum
hobby shop
building supply store
monobasic
calcium sulfate
Countertop Chemistry
The Science House, NC State University
79
Appendix
COMPOUND
carbon
FORMULA
COMMERCIAL
EQUIVALENT
SOURCE
C
CO2
charcoal,graphite
hardware store
dry Ice
dairies, grocery store
H2CO3
C6H8O7
soda water
grocery store
sour salt
grocery store
Cu
CuSO4 •5H2O
sheet, pipe or wire
hardware store
Bluestone™ algaecide
Root Eater™
hardware or lawn &
garden center
(CH3)2SO
C2H5OH
solvent
drug stores
Everclear™
liquor store
CH3CH2OH
CH2OHCH2OH
denatured alcohol
hardware or paint shop
antifreeze
auto supply store
fruit sugar
grocery store
glucose
C6H12O6
C6H12O6
dextrose
drug store
glycerol
C3H8O3
glycerin
drug store
helium
He
helium
party shops
hydrochloric acid
HCl (aq)
muriatic acid
masonry cleaner
hardware store or lawn &
garden store
hydrogen peroxide
H2O2
3% antiseptic peroxide
Clairoxide (12%)
drug stores
beauty supply store
beet juice, red cabbage
juice, cherry juice
grocery store
carbon dioxide-solid
carbonic acid
citric acid
copper
copper sulfate,
pentahydrate
DMSO
95% ethanol
ethanol/ethyl alcohol
ethylene glycol
fructose
indicators
iodine
I2
iodine
drugstore
iron
Fe
uncoated nails, filings
steel wool
hardware store
iron (III) chloride
FeCl3
C3H6O3
none
drug store
milk acid
grocery store
fishing line sinker
sporting supply store
magnesium hydroxide
Pb
Mg(OH)2
milk of magnesia
drug store
2-propanol
CH3CH(OH)CH3
rubbing alcohol
drug store
lactic acid
lead
Countertop Chemistry
The Science House, NC State University
80
Appendix
COMPOUND
FORMULA
COMMERCIAL
EQUIVALENT
SOURCE
magnesium sulfate,
heptahydrate
MgSO4•7H2O
Epsom salts
drug store
methanol
CH3OH
methyl alcohol,
duplicator fluid,
gasoline “dryer”
paint store
office supply store
auto supply store
methylene blue
C16H18CN3S
methidote antiseptic
biological stain
veterinarian
tropical fish store
naphthalene
C10H8
moth balls
hardware store
nujol
mineral oil, baby oil
drug store
vegetable oil
grocery store
oxalic acid
Hydrocarbon
(formula varies)
C2H2O4
rust remover
radiator cleaner
drug store
hardware store
para-dichlorobenzene
C6H4Cl2
moth flakes
hardware store
paraffin wax, candles
grocery store
oil
paraffin
C19 H19SO5
swimming pool indicator
H3PO4
pH Down (30% solution)
KAl(SO4)2•12H2O potassium alum
swimming pool supply
potassium bitartrate,
potassium hydrogen
tartrate
KHC4H4O6
cream of tartar
grocery store
potassium bromide
KBr
K2CO3
potassium bromide
photo store
potash
agricultural supply store
lite salt
none
grocery store
potassium dichromate
KCl
K2Cr2O7
potassium hydroxide
KOH
caustic potash
hardware or ceramic
phenol red
phosphoric acid
potassium aluminum
sulfate
potassium carbonate
potassium chloride
tropical fish store
photo supply store
photo supply store
shop
potassium nitrate
Countertop Chemistry
KNO3
saltpeter
The Science House, NC State University
drug store
81
Appendix
COMPOUND
FORMULA
potassium permanganate KMnO4
NaHCO3
sodium bicarbonate,
COMMERCIAL
EQUIVALENT
SOURCE
"Clearwater" (53% soln.) tropical fish store
baking soda
grocery store
grocery store
sodium hydrogen
carbonate
sodium carbonate
Na2CO3
washing soda
sodium chloride
NaCl
plain table salt -uniodized grocery store
sodium hydroxide
NaOH
drain opener (LYE)
hardware store
or farm supply store
sodium hypochlorite
bleach (5% Sol’n)
grocery store
sodium nitrate
NaClO
NaNO3
Chile saltpeter
garden supply store
sodium phosphate
Na3PO4
trisodium phosphate
(TSP)
paint or garden shop
sodium silicate
Na2SiO3
water glass
hardware store
sodium tetraborate
decahydrate
Na2B4O7.10 H2O borax
grocery store
sodium thiosulfate
Na2S2O3
hypo
photo store
stearic acid
candle hardener
hobby shop
sucrose
C17H35CO2H
C12H22O11
table sugar
grocery store
sulfur
S
sulfur
lawn & garden shops
tin or copper
Sn, Cu
metal sheets
hardware store
builders supply store
gardening soil
lawn & garden center
galvanized nails
hardware store
vermiculite
zinc
Zn
Countertop Chemistry
The Science House, NC State University
82