Sponsored by Hawai`i Space Grant Consortium, Hawai`i Institute of Geophysics and Planetology, University of Hawaii, 2001

PRINGLES CAN ROCKET
Created by Dale Olive and Randy Scoville
Future Flight Hawai`i instructors

Demonstration at a glance:
A Pringles can made to look like a rocket is filled with hydrogen gas and lit. After a while, the can flies upwards after a loud explosion is heard.

Set-up:
Turn the empty Pringles can upside down and make a hole in the center of the aluminum bottom with a nail. On the lid side of the can I make four holes with a nail equidistant from eachother about one centimeter up from the lid. You're now ready to fill the can with hydrogen. Place a small piece of tape over the hole you punched in the bottom (now the top.) I fill the can with hydrogen gas generated the same way as the hydrogen balloon demo without the thistle tube and balloon attached. When I see that the can is full, when gas is pouring out the four holes in the bottom, I remove the can from the hydrogen gas generator and place on top of its plastic lid. Removing the tape quickly, I light the gas coming out of the small hole on top with an extended lighter or match taped on a long stick. You can see the flame burning for a while until it seems to disappear into the can followed by a loud boom and flight of the can.

Theory:
Like the last demo with the hydrogen balloon all you're producing in this reaction is water. Remember the equation:

2H2 (g) + O2 (g) > 2H2O (g)

The reason why the flame only burns on top of the can for a little while is because the gasses inside the can are not at the correct ratio for the reaction to occur. As the hydrogen gas is burning upwards through the hole in the top, air is going in through the four holes in the bottom. When the ratio of H2 to O2 reaches 2 to 1 (as seen in the reaction above,) the reaction occurs producing a lot of energy and a little film of water that can be felt inside the can.

Extension:
The main fuel tank on the space shuttle uses liquid hydrogen and oxygen to propel it into space. The reason why the discovery of water on the Moon and Mars is so important is because it can be split into hydrogen and oxygen to be used for fuel for the return journey home.


Index of Activities.

http://www.soest.hawaii.edu/spacegrant/ScienceDemos/
Communications: Hawaii Space Grant Office
This activity is featured in Future Flight Hawaii, a K-12 Education Project of Hawaii Space Grant Consortium.
FEB 27 2001.