Plan
- How can you keep track of changes before, during and after this experiment?
- What do you think is going to happen? (Guessing what is going to happen during an experiment is called a ‘prediction’ or ‘hypothesis’)
- Will you do this experiment in pairs or small teams?
- What supplies will you need for this experiment?
Do
- Safety first! Start by putting on your safety glasses.
- Place your plastic bottle in the tray or tub for easy clean up.
- Measure ½ cup of hydrogen peroxide and pour it into the bottle.
- Add a big squirt of dish soap to the bottle and swirl it gently to mix
- If you want to add food colouring, add a few drops of food colouring to the bottle.
- In a measuring cup, mix together one tablespoon of yeast and three tablespoons of warm (not hot!) water. Stir for about 30 seconds.
- Pour the yeast mixture into the bottle then quickly step back and watch your reaction go!
Review
- What happened when you added the yeast mixture to the hydrogen peroxide?
- Was your prediction correct? What happened?
- When hydrogen peroxide comes into contact with yeast, it starts breaking down into water and oxygen. Oxygen is a gas and wants to escape the liquid. The dish soap traps these bubbles and makes a foam.
Materials
- Empty plastic bottle per pair or team
- A stir stick that will fit through the opening of the bottle
- Dry yeast
- Warm water
- Liquid dish soap
- 3% hydrogen peroxide
- Measuring cups
- Measuring spoons
- Safety glasses
- Large tub or tray to catch the foam
- Garbage bags to go under the tray in case of overflow
- Liquid food colouring (optional)
- Different-shaped bottles or glasses (optional)
Keep it Simple
- Do this experiment as a big group or in Lodges/Lairs. Work together to measure out the ingredients carefully with the help of a Scouter.
Take it Further
- Try changing some elements of this experiment to see what changes. What happens if you do not add the dish soap? What happens if you put the ingredients into a differently-shaped bottle
