- clean empty recycled soda bottle
- vinegar (or lemon juice)
- baking powder
- safety goggles
Show the students a balloon that is not inflated. Brainstorm ways to blow up the balloon. (blow air into the balloon, fill it with helium, etc.) Discuss that all these ideas are ways to use a GAS to fill up a balloon.
Show the students an empty recycled soda bottle, vinegar and baking soda. Have the students brainstorm ways to use these new materials to blow up the balloon. Have the students predict what will happen when they put vinegar and baking soda into the bottle.
- Put on safety goggles.
- Stretch the balloon to make it easy to inflate.
- Pour 1 ounce of vinegar into the bottle.
- Pour 2 teaspoons of baking soda into the balloon.
- Carefully fit the balloon over the mouth of the soda bottle without letting any baking soda fall into the bottle.
- After the balloon is completely over the mouth of the bottle, let the baking soda fall into the bottle.
- Observe the balloon expand!
- Have the students explain what happened.
When baking soda and vinegar (or lemon) are mixed, they form a GAS (carbon dioxide) that rises up into the balloon and inflates it.