Foam it! Cause a Chemical Reaction

This experiment uses a yeast solution, liquid detergent such as Dawn, 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 turns 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!

• 16 oz. empty plastic soda bottle
  
• Hydrogen peroxide (6% solution, purchased from a beauty supply store)
  
• Liquid detergent (Dawn^®)
  
• Food coloring
  
• 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 good practices to have your child wear safety glasses whenever they conduct any type of activity that involves working with chemicals)

1. 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.
   
2. Next add 3-4 drops of food coloring to the peroxide and pour the peroxide through the funnel into the bottle.
3. Add the Dawn liquid detergent to the peroxide in the bottle.
4. 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 this is an example of an exothermic (heat producing) reaction.