Dry Ice: #4 Balloons!

The balloon at the beginning of the day

This is the fourth segment in a series on dry ice experiments. CLICK HERE FOR SAFETY INFORMATION.

For our next experiment, I broke apart the large 5 lb block of dry ice with a metal putty knife and a hammer while a kid stretched out a balloon.

An adult then held open the mouth of the balloon while I, using the tongs, dropped in small pieces of dry ice. The balloon was then carefully tied off.

The balloon a few minutes later

Over time, the dry ice sublimated and filled the balloon with gaseous carbon dioxide. As this happened, the balloon expanded. It didn't float (carbon dioxide is more dense than air, remember), but it was neat to set it in the middle of the table and watch it grow as we performed other demonstrations and experiments.

We tried to make the balloon pop, but we were unable to get enough dry ice into the balloon before it
became difficult to tie. My son had the greatest success with this by crushing the dry ice and pouring it in. Even so, the balloon merely expanded to a large size; it didn't pop.

If you really want to make it pop, you will probably need to place the balloon (with dry ice) in a bowl of warm water, as seen in the video below: