This document outlines how the activity might be linked to the NGSS as part of a classroom lesson.
This experiment would work well with students from 4th to 8th grade. It covers standards such as energy transfer between the reaction and the environment, how energy can measured in the form of temperature, the creation of new substances from old ones and the properties of different states such as liquid, solid and gas. It also focuses on the use of catalysts and the explanation behind why we use them. Science Discipline(s) Chemistry Topics Exothermic reactions, oxidation and reduction reactions, and catalysts. Activity Title Elephant toothpaste Materials
- ½ cup of 6 % Hydrogen Peroxide (1 cup if using 3%)
- Large soda bottle
- Liquid soap
- Food coloring
- 1 package of 8 oz. active yeast
- 3 tablespoons of warm water
- Overflow box
- Paper towels
- Add yeast and water in a container or cup, stir then let it sit for a few minutes.
- Place the plastic bottle in the cake pan or overflow box and pour approximately 1⁄2 cup of hydrogen peroxide into the plastic bottle/container.
- Add 2-3 squirts of dish soap to hydrogen peroxide to the bottle/container. Swirl the mixture in the container to mix it up a bit.
- Quickly add the yeast mixture to the bottle/container.
- Foam will begin to shoot up and out of the bottle and into the container. The kids can place their hands on the bottle to feel the change in temperature and can also play with the suds.
- What would happen if we changed the amount of yeast being used?
- What are the important components of this reaction? How would you design an experiment to test which are important components?
- How would changing the amount hydrogen peroxide affect the amount of foam created or how quickly it formed? How would you test this hypothesis?
- What would happen if you didn’t add soap to the mixture?
- How would adding dry yeast differ from yeast that was mixed with warm water?
- How would changing the shape of the bottle to a cup change what happened in the reaction?
- Why is there steam coming off of the foam?