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

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

Demonstration at a glance:
An empty soda can be easily ripped clean in two. This can be used to impress possibly hostile students on the first day of class??

Set-up:
Remove the tab off an empty clean soda can. With a screwdriver or other sharp object "scratch" a circle around the inside middle of the soda can. Pour in a solution of copper (II) chloride to a depth up to the scratch and let sit for a few minutes. Pour out the copper (II) chloride solution and rinse the can. It is now ready for ripping.

Theory:
The need for the scratch around the inside of the can is due to the fact that soda cans contain a plastic lining which protects the can from the acidic soda. The copper chloride solution is involved in a single replacement reaction with the aluminum in the can as follows:

3CuCl2 (aq) + 2Al (s) > 3AlCl3 (aq) + 3Cu (s)

After the reaction, the can is basically being held together by the outside paint and a thin film of copper.

Extension:
The presence of a plastic lining has impressed my students for years. To see it more effectively, place a soda can full of water in a strong solution of HCl and the aluminum will be dissolved leaving the plastic lining and what's left of the can. This should be done under a fume hood or in a well ventilated area away from students as a lot of vapor is given off and a lot of heat produced (thus the need for water to prevent the lining from melting.)


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.