Things Required:
A thermometer
A small bowl
1 tablespoon quick-rising dry yeast
1/4 cup of hydrogen peroxide
A spoon
Pencil and paper
Directions:
Record the temperature showing on the thermometer, and then place it in the bowl. Pour in the hydrogen peroxide, add the yeast, and stir the solution. As you watch what happens, feel the lower sides and bottom of the bowl. Wait for a minute or two; then spoon out the thermometer and record the temperature again.
This Is What Happens:
The solution foams up and bubbles, and the bottom and sides of the bowl feel very warm. Steam can be seen coming from the solution. The higher thermometer reading shows that heat has been produced.
Science Behind It:
When yeast and hydrogen peroxide mix chemically, the hydrogen peroxide changes into oxygen and water molecules. The bubbles are produced by the oxygen gas escaping during the chemical change. This change also produces heat. When heat is produced in a chemical change, we call the process exothermic.
