This is a simple experiment that shows chemical reactions can produce heat.
Things Required:
Thermometer, outdoor or cooking type
Small baby food jar
Powdered bleach
Teaspoon
Directions:
Fill the jar with water. Add one teaspoonful of powdered bleach and stir. Insert the thermometer into the liquid. Observe the thermometer every minute for 10 minutes.
This Is What Happens:
The temperature rises, stops and then lowers.
Science Behind It:
Adding water to powdered bleach starts a chemical change in which oxygen is slowly given off. Heat is also released during this change. The thermometer is a way of observing this heat release. The temperature rises as long as heat is being produced and stops rising when the heat production stops. There is a lowering of the temperature as the heat in the liquid is lost to the air in the room. The temperature of the liquid will finally become the same as that of the air in the room.
