Energy stored in chemicals can be released and converted into work.
(For each group of 4 students)
2 film cans or other small containers
1/2 teaspoon measurer
Double-acting baking powder
1. Fill a film can 3/4 full with water.
2. Pour the water from the film can into a balloon.
3. Repeat #1 and #2 to fill up the second balloon.
4. Dry the film can with paper towels.
5. Put 1/4 teaspoon baking powder into one film can and 1/2 teaspoon baking powder into the other can.
6. Stretch one balloon over the top of each can.
7. Dump the water from each balloon into the can.
8. Watch what happens and draw a picture to record your results.
The baking powder has STORED energy. When the baking powder reacts with the water, this energy is released. The released energy does the work of making the balloon inflate. The more baking powder you use, the more energy will be released and the bigger the balloon will get.
The stored energy released when the baking powder reacted with the water is CHEMICAL energy. The reaction makes carbon dioxide gas. As the balloon fills up with the gas, the chemical energy is being converted to mechanical energy.
Fill a film can 3/4 full of water. Set the can on the floor. Put 1/2 teaspoon baking powder. Quickly put the lid on and snap it tight. Stand back and watch!