8
THE CHEMISTRY OF PAINTBALLS
LABORATORY EXPERIMENT
In chemistry there is a saying that “like dissolves like.” This means that substances that are
similar in chemical properties mix well with each other. One of the most common properties for
which this statement exists is polarity. Recently we’ve come to learn that water is a polar
molecule. Therefore, water can mix with other polar substances and not with nonpolar
substances. So let’s test out this theory and put it to a real-life test – with paintballs! Along the
way, we’ll discover some other properties of paintballs as well.
SAFETY
Lab goggles and aprons must be worn at all times. Do not throw paintballs!!! You will receive
a zero for this lab if you do!!!
PROCEDURE A – THAT’S SWELL
How much water can a paintball absorb?
1. Measure the mass of one paintball.
2. Put the paintball in a 250-mL beaker and fill it half-full with water.
3. Let the paintball sit in the water while you complete the rest of the lab. However, you
must stir the paintball every few minutes or it will stick to the bottom of the beaker and
burst.
4. After 30 minutes, take the paintball out of the water, carefully dry it, then weigh it.
PROCEDURE B – PIG’S SKIN
What is a paintball shell made of?
1. For this experiment, you need to separate the shell from the paint. (Mr. D’s BlowtorchNail method)
2. Squeeze out several drops of paint into test tube #1. Add a small amount of water.
3. Place a smallish piece of the paintball shell into a test tube #2. Fill it with 1-cm of water.
4. In test tube #3, place a small scoop of gelatin and fill it with 1-cm of water. Flick the test
tube to mix.
5. Place two drops of Biuret Reagent into test tubes 1-3. Note the results in your data
table.
PROCEDURE C – POLAR OPPOSITES
What is the polarity of paintball paint?
1. In test tube #4, mix 1-cm water and 1-cm oil. Note the results.
2. In test tube #5, squeeze out several drops of paint from a paintball and mix it with 1-cm
of water. Flick to mix. Note the results.
3. In test tube #6, squeeze out several drops of paint from a paintball and mix it with 1-cm
of mineral oil. Flick to mix. Note the results.
CLEANUP
-
Paintball shells must be thrown into the garbage – do not put them in the sink.
Scrub each test tube with soap and water. Use a test tube brush.
Wash your lab apron and lab bench.
Clean up any additional paint that you see.
DATA TABLE A
Time
Mass of paintball
DATA TABLE B
Object
Observation
Paintball shell after breaking (Step 1B)
Test tube with shell + Biuret Reagent
Test tube with paint + Biuret Reagent
Test tube with gelatin + Biuret Reagent
DATA TABLE C
Object
Observation
Oil + water
Paint + water
Paint + oil
ANALYSIS QUESTIONS
Read the Paintball article and answer the following questions using complete sentences.
1. How much water is absorbed by the paintball during the course of the lab? From the
article, explain how the water got into the paintball.
2. The Biuret Reagent in Procedure B is used to test for the presence of protein. If protein
is present the solution turns blue-violet. Gelatin is a protein made of collagen. We used it
in this lab as a positive control. From your results in Procedure B and the article, can you
confirm the presence of protein in the paintball shell and/or paint? Explain.
3. Like dissolves like. Is the paintball paint polar or nonpolar? Provide evidence for your
answer from the lab and article.
4. What role does hydrogen bonding play in the chemistry of paintballs?