The foam your kids will create in this experiment resembles toothpaste being squeezed from a tube—just be sure they don’t get it in their mouth!
What You’ll Need:
- A clean 16-oz plastic soda bottle
- 1/2 cup 20-volume hydrogen peroxide liquid (20-volume is a 6% solution; you can get this from a beauty supply store or hair salon)
- 1 Tablespoon (one packet) of dry yeast
- 3 Tablespoons of warm water
- Liquid dishwashing soap
- Food colouring
- Small cup
- Safety goggles
What To Do:
Note: As you can see from the picture, foam will overflow from the bottle, so be sure to do this experiment on a washable surface, or place the bottle on a tray.
- Hydrogen peroxide can irritate skin and eyes, so put on those safety goggles! An adult should carefully pour the hydrogen peroxide into the bottle.
- Add 8 drops of your favourite food colouringa into the bottle.
- Add about 1 tablespoon of liquid dish soap into the bottle and swish the bottle around a bit to mix it.
- In a separate small cup, combine the warm water and the yeast together and mix for about 30 seconds.
- Now the adventure starts! Pour the yeast water mixture into the bottle (a funnel helps here) and watch the foaminess begin!
Foam is awesome! The foam is special because each tiny foam bubble is filled with oxygen. The yeast acted as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since it did this very fast, it created lots and lots of bubbles. Ask if your kids noticed the bottle got warm? The experiment created a reaction called an exothermic reaction, which means it not only created foam, it created heat! The foam produced is just water, soap, and oxygen, so you can clean it up with a sponge and pour any extra liquid left in the bottle down the drain.
The experiment can also be done with the hair care version of hydrogen peroxide, or the weaker pharmacy version, although the effect with the pharmacy version will be smaller. Readers should use safety goggles for any experiment, and should have adults read instructions on containers for safety precautions.