A fun foamy reaction experiment where yeast breaks down hydrogen peroxide to create a massive “toothpaste” eruption. Safe for kids when using 3% hydrogen peroxide
Difficulty Level: Easy
Concepts: Chemical Reactions
Materials List
- Hydrogen peroxide (3% – safe, household grade)
- 1 packet dry yeast (or 1 tablespoon)
- Warm water (to activate the yeast)
- Liquid dish soap
- Food colors
- A plastic bottle or tall container
- Tray to contain the foam
- Funnel (optional)
- Safety Glasses
Steps
- Place the bottle on a tray.
- Add ½ cup of 3% hydrogen peroxide into the bottle.
- Add a few drops of food coloring.
- Add 1–2 tablespoons of dish soap and gently swirl.
- In a separate cup, mix dry yeast with warm water to activate it.
- Quickly pour the yeast mixture into the bottle.
- Watch the thick, colorful foam push out like “elephant toothpaste”!
Science Behind It
Hydrogen peroxide naturally breaks down into oxygen + water, but yeast contains the enzyme catalase, which makes the reaction happen much faster.
2 H₂O₂ → 2 H₂O + O₂ (gas)
2 H₂O₂ → 2 H₂O + O₂ (gas)
- The oxygen gas gets trapped inside the dish soap.
- This creates a huge amount of foam, pushing upward like toothpaste for an elephant.
- The reaction feels warm because it is exothermic (releases heat).
Using 3% hydrogen peroxide makes it safe and kid-friendly.
Watch the video!
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