Foam It! Cause a Chemical Reaction
This experiment uses a yeast solution, liquid detergent, and hydrogen peroxide to produce an exciting reaction like no other! The result will send a stream of foam shooting up out of a bottle and, after a minute or so, begin turning into a moving stream that resembles toothpaste being squeezed from a tube. You may not want to use this foam to brush your teeth, but you'll certainly “foam up” your child's imagination and love of science!
What You Need:
- 16 oz. empty plastic soda bottle
- 20 ml (0.675 fluid ounces) hydrogen peroxide (6% solution, purchased from a beauty supply store)
- 10 ml (0.3382 fluid ounces) dishwashing liquid (such as Dawn)
- Food coloring
- 1 oz. package of powdered yeast
- Small Funnel
- Aluminum foil cake pan with 2-inch sides
- Safety glasses
Although the following activity is safe, it is always a good practice to have kids wear safety glasses whenever they conduct any type of activity that involves working with chemicals.
What You Do:
- Have your child place the empty plastic soda bottle into the center of empty aluminum cake pan and then put the funnel into the bottle’s mouth.
- Next add 3–4 drops of food coloring to the peroxide and pour the peroxide through the funnel into the bottle.
- Add the dishwashing liquid to the peroxide in the bottle.
- Pour the yeast mixture into the bottle and quickly remove the funnel. Have your child touch the bottle to feel if any temperature changes are taking place.
After a minute or two foam will shoot up out of the bottle, run into the pan, and eventually begin to come out in a steady stream. Encourage your child can play with the foam; it's just soap and water with oxygen bubbles! The bottle will feel warm to the touch as you've just witnessed an example of an exothermic (heat-producing) reaction.
Hydrogen peroxide, when mixed with a liquid detergent and a catalyst (yeast), will react producing foam (oxygen gas) regardless of amounts used, so encourage your child to experiment with different amounts to see which will produce the most foam!