What is elephant toothpaste?
Is it a toothpaste to clean the elephant’s teeth? Before I get some information about it, it was just a toothpaste of elephant that I thought it did. It is an experiment called elephant toothpaste due to its “volcano of foam”. It looks like toothpaste squirting out of a tube. It is so big that only an elephant could use toothpaste this large. So please don’t brush your teeth with it!
Because it requires only a small number of ingredients and makes a “volcano of foam”, this is a popular experiment for children to perform in school or at parties.
How to make elephant toothpaste?
Materials:
· Empty plastic bottle (or another container)
· 3% hydrogen peroxide solution (available at nearly any store)
· Dry yeast (from the grocery store)
· Liquid dishwashing detergent
· Warm water
· Food coloring (optional, but it looks nice)
· Safety goggles
· different-shaped bottles or glasses (optional)
Procedure
1. Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food coloring into the bottle. Swirl the bottle around to mix up the ingredients. Set the bottle in a sink or outdoors or some other place where you won’t mind getting wet foam everywhere.
2. In a separate container, mix a packet of dry yeast with a little warm water. Give the yeast about five minutes to activate before proceeding to the next step.
3. When you are ready to do the demo, pour the yeast mixture into the bottle. The reaction occurs immediately upon the addition of the yeast.
4. Try the activity with different-shaped containers. To use a bottle with a narrower or wider neck—or a cylindrical drinking glass with no neck, you will get more effect.
Chemical explanation
Foam is awesome! This experiment shows the decomposition of hydrogen peroxide with the catalyst. How rapidly the reaction proceeds will depend on the concentration of hydrogen peroxide. Hydrogen peroxide (H2O2) decomposes into water and oxygen gas, which is in the form of foam, but normally the reaction is too slow to be easily perceived or measured, therefore we add some catalyst to promote this process. The role of liquid dishwashing detergent is to increase the tension of foam. You also can drop one or more kinds of food coloring to make it more interesting. The reaction is summarized by this formula:
2 H2O2 –> 2 H2O + O2.
Note
You must put on safety goggles before you start to do this experiment; you’d better put all your materials in the location where you plan to do your activity. Place your bottle on the tray or tub so that you can clean up all the foam easily.