I’ve been hearing about this science demonstration for years, and finally decided to try it! If you do it at home, kids should wear safety goggles or sunglasses to protect their eyes, and adults should pour the 3% hydrogen peroxide into the bottles.
a tray or cookie sheet
3% hydrogen peroxide (available at most pharmacies and discount stores)
liquid dish soap
dry yeast (2 packets)
empty 16 oz bottle
What to do:
1. Pour 1 cup hydrogen peroxide into an empty 16oz bottle. (A funnel helps!)
2. Add 2 Tbs. liquid dish soap to the bottle and mix well with the hydrogen peroxide.
3. Put 8 drops of food coloring into the bottle and swirl to mix.
4. Position the bottle on the tray.
5. Pour 2 packets of yeast into a paper cup and pinch the cup’s lip to make a pouring spout.
6. Quickly pour the yeast into the bottle, while swirling the liquid vigorously to mix well. The better you mix it, the better the experiment will work!
7. Set the bottle down on the tray before the foam emerges from the top.
8. Watch the chemical reaction between catalase in the yeast and the hydrogen peroxide create oxygen bubbles in the soap!
9. When the reactions has stopped, have an adult clean up the mess by pouring everything down the sink and rinsing the tray with water. (Normally kids should clean up, but for this one, I’d recommend an adult do it.)
The Science Behind the Fun:
Hydrogen Peroxide (H2O2) is a common household chemical that is often used to disinfect wounds and bleach hair. Certain chemicals can break it down into water (H2O) and Oxygen (O).
Dry yeast is a living fungus that produces a molecule called catalase. Catalase is very good at breaking down hydrogen peroxide quickly. When you add yeast to hydrogen peroxide that’s been mixed with liquid soap, the soap traps the oxygen and makes bubbles that push their way out of the bottle.
You may notice that the bottle feels warm. That’s because the chemical reaction produces heat and is called an exothermic reaction.