Elephant Toothpaste

Perkins School for the Blind Secondary school student Kendra Hammer shares her science fair project.

I chose elephant toothpaste as my science experiment because it’s tactile for the students who can’t see. I also chose this experiment because it is very fun to make and I love watching the end result and seeing the foam shoot up into the air.

Here are some of the vocabulary words that I used in my experiment:

Hydrogen peroxide: which is a colorless liquid and is slightly more viscous than water.
Food coloring: which adds color to any food or drink. Liquid dish soap, which is primarily used for hand washing of glasses, plates, cutlery, and cooking utensils.
Yeast: which made up of tiny micro-organisms. Yeats are in the same family as the mushroom. Yeasts use sugars and starches as food sources. Yeast can also be used as a catalyst.
Catalyst: which is something that can be used to make a chemical reaction happen faster.

When people visit my table at the science fair, I plan to have the elephant toothpaste already made and ready. Then when people walk by, I plan to have the students feel the toothpaste so that the students can examine it and see and describe what they think it feels like.

student with elephant toothpaste poster board — *Student with elephant toothpaste poster board*

*Student holding elephant toothpaste at Science Fair*

Materials

Erlenmeyer Flask
120 mL (6%) hydrogen peroxide liquid
15 mL dry yeast
45 mL warm water
15 mL liquid dish washing soap
Food coloring
Tray
Apron
Safety goggles
Stirring rod
Small beaker
Funnel
Large bucket

Preparation

Pre-measure everything and set up on tray
In a separate small beaker, mix yeast with 45 mL of lukewarm water.

student feeling the elephant toothpaste — *Student feeling the elephant toothpaste*

Procedure

Pour the hydrogen peroxide into the flask using the funnel.
Add 12 drops of food coloring into the flask.
Add about 15 mL of liquid dish soap into the flask and swish the bottle around a bit to mix it.
Place flask in a deep bucket to collect foam. Then pour the premixed yeast/ water mixture into the flask.
Observe the reaction.
Feel the flask.

Observations & Conclusion:

Once I added everything together into the flask, and once it created the foam, I noticed that the foam was very runny. I noticed the flask felt warmer.
What can I add to the foam to make it thicker?

Variations

Experiment #2:

Add more dish soap: (30mL)

Produced 2 liters of foam. The foam came out slower and was more thick and the flask felt hot.

Experiment #3:

Added 175 mL of hydrogen peroxide

Once I doubled the amount of hydrogen peroxide to 175 mL, the foam tripled in size and filled 3 liters. The thickness of the foam was very similar to the second experiment.

NGSS Standards:

HS-PS1-5. Apply scientific principles and evidence to provide an explanation about the effects of changing the temperature or concentration of the reacting particles on the rate at which a reaction occurs.

HS-PS1-6. Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium.