Elephant Toothpaste
Purpose:
The purpose of this lab was to mix two solutions together and form a foam fountain.
When performing this experiment, just by changing one material can give you similar
results.
Materials A:
 A clean 16 ounce plastic bottle
 1/2 cup (118ml) 3% hydrogen peroxide
 1 Tablespoon (one packet) of dry yeast
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3 Tablespoons of warm water
1 Tablespoon liquid dish washing soap
Food coloring
Small beaker
Safety goggles
Tray
Funnel
Disposable gloves
Plastic spoon
Materials B:
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A Clean 16 ounce plastic bottle
Food coloring
40 ml of Liquid dish washing soap
80ml of 3% hydrogen peroxide
1 Tablespoon of Potassium Iodide
Disposable gloves
Funnel
Tray
3 Tablespoons of warm water
Beaker
Goggles
Plastic spoon
Elephant Toothpaste
Procedure A:
1. Put on safety goggles and gloves.
2. Place plastic bottle onto tray.
3. Carefully pour ½ a cup of the 3% hydrogen peroxide into the 16 ounce plastic
bottle.
4. Add 8 drops of food coloring into the bottle.
5. Add 1 tablespoon of dish soap into the bottle.
6. Swish the bottle around to mix it.
7. Put aside.
8. Add 3 Tablespoons of water to an empty beaker.
9. Add 1 Tablespoon of yeast to the water.
10. Mix with a plastic spoon for about 30 seconds.
11. Pour the mixture of water and yeast into the bottle using a funnel.
12. Observe the reaction.
13. Disposal: Leave the gloves on while cleaning up. Rinse the foam in the bottle
down the sink.
Procedure B:
1. Put on safety goggles and disposable gloves.
2. Place the plastic bottle onto the tray.
3. Add 2 tablespoons of potassium iodide into the 16 ounce plastic bottle.
4. Then add 3 tablespoons of water to the bottle.
5. Close the bottle and shake until all the potassium iodide is dissolved.
6. Set aside.
7. Pour 80 ml of 3% hydrogen peroxide into a beaker.
8. Add 40 ml of dish soap to the hydrogen peroxide.
9. Swirl to mix.
10. Add 8 drops of food coloring to the beaker.
11. Using the funnel add the hydrogen peroxide to the plastic bottle.
12. Observe the reaction.
13. Disposal: Leave the gloves on while cleaning up. Rinse the foam in the bottle
down the sink.
Elephant Toothpaste
Date and Observations:
Experiment A:
Experiment B:
Hydrogen peroxide molecules are very
unstable and naturally decompose into
water and oxygen gas. The chemical
equation for this decomposition is:
The overall equation for this reaction
is 2 H2O2(aq) --> 2 H2O(l) + O2(g)
hydrogen peroxide
2H2O2
→ water + oxygen
→ 2H2O +
O2
The yeast acted as a catalyst to remove
the oxygen from the hydrogen peroxide.
Since it did this very fast, it created lots
and lots of bubbles.
The decomposition of the hydrogen
peroxide into water and oxygen is
catalyzed by the iodide ion.
H2O2(aq) + OI-(aq) --> I-(aq) + H2O(l) + O2(g)
This had a soapy scent of apples due to
the dishwashing soap
The dishwashing detergent captures
the oxygen as bubbles.
Each tiny foam bubble is filled with
oxygen.
Food coloring changed the foam to a
blue-green color.
Food coloring changed the foam to a red-
Had a fresh baked bread scent.
yellow color.
The experiment created a reaction called
The experiment created an
an exothermic reaction.
exothermic reaction as well.
-that means it not only created foam, it
also created heat!
-the bottle was warm as well.
Elephant Toothpaste
Analysis Questions:
1. What does a catalyst do in a chemical reaction?
A. Catalysts help a reaction happen faster but do not change themselves during
the reaction.
2. What clues did you have that a chemical reaction occurred in this activity?
A. The bubbling and the heating of the bottle are examples of a chemical
reaction.
3. What evidence do you have that hydrogen peroxide decomposed faster when you
added yeast?
A. Bubbles of oxygen gas were produced after the yeast was added.
4. Why is warm water best to use in this experiment?
A. Warm water is best for yeast because yeast is a living organism that likes to
live in similar temperatures to humans. Put yeast in hot water and it dies, put it in cold
water and it will not do its job properly (will be too cold to reproduce fast).
5. What is actually all happening?
A. Hydrogen peroxide is H2O2, which means it is water (H2O) with one extra
oxygen. When yeast is added, it acts as a catalyst to split the hydrogen peroxide into
water and oxygen. Bubbles of oxygen are trapped in the soap, which transforms into
the foam fountain. The product formed is just soap, water, and oxygen.
Elephant Toothpaste
Conclusion:
This experiment used hydrogen peroxide and potassium iodide (yeast was used in
experiment A), mixed with dish soap and water. If you add all these together, the
hydrogen peroxide's decomposition is sped up by the catalyst, potassium iodide (yeast
in experiment A). Oxygen is given off and forms foam with the dish soap. The foam
pushes up in the bottle and comes out the top looking like toothpaste. An exothermic
process releases heat, and causes the temperature of the immediate surroundings to
rise. The process of the bottle warming up is one example of an exothermic process.
The formation of bubbles is also an example of this. It is an exothermic
reaction because the fizzing is carbon dioxide which is being released as heat. A
catalyst is a substance that increases the rate of a chemical reaction without itself
undergoing any permanent chemical change. Both experiments had many similarities
rather than differences. Some similarities were they both started off producing foam
right away once the hydrogen peroxide was added. The soap added was settled at the
bottom. The bottle was also warm for both experiments. The smells were different,
the yeast one smelled like fresh baked bread and the Potassium Iodide one smelled just
like the dish soap added which was the smell of apples. The Potassium Iodide
experiment looked a bit watery compared to the yeast experiment. The main goal was
to produce foam and they both did as so.