Blow up a Balloon with Dry Ice

Try blowing up a balloon using dry ice! Dry ice can blow up a balloon by filling it with carbon dioxide as the dry ice sublimates.

How could something as cold as dry ice blow up a balloon?

Remember that dry ice expands into carbon dioxide gas when it sublimates, or turns into a gas. This experiment shows you how that works. Make sure to follow all dry ice safe handling precautions.

What you need for this experiment:

• Balloons with openings large enough to fit a plastic bottle opening
• Empty plastic water or soft drink bottle
• Small pieces or pellets of dry ice
• Gloves and tongs to hold the dry ice
• Two people

What to Do:

1. Blow up one of the balloons and tie it off.
2. Save the balloon for later.
3. Remove the lid of the plastic bottle.
4. Have one person hold the plastic bottle upright.
5. Using tongs and wearing insulated gloves, take a few small pieces of dry ice and put them into the plastic bottle.
6. Fit a balloon over the opening of the bottle.
7. Watch the balloon inflate with carbon dioxide as the dry ice sublimates.
8. To make the balloon inflate faster, shake the bottle gently.
9. When the balloon is fully inflated, remove it from the bottle and tie it off.
10. Go and get the first balloon that you blew up with your own breath.
11. Toss up both balloons into the air.

Notice how the balloon filled with carbon dioxide gas falls quickly to the ground?

That's because carbon dioxide is heavier than air.

Wearing insulated gloves and using tongs, pick up a piece of dry ice and touch it to the balloon that you blew up with air (not the one you filled with carbon dioxide). What happens to the balloon?

Can you guess why?