The University of Illinois
 

 

Home
Welcome
Course Web Sites
Location
Lecture Demos
Services Staff History 3-D Molecules Online Resources

 

 

Return to Lecture Demos page

Collapsing Can

photo, collapsed coca cola can

Why does a Coke can filled with steam collapse in cold water?

photo, cans filled with water on hot plate
Coke cans containing a small quantity of water are heated until the water boils. Steam (gaseous water), fills the can and pushes the air out the hole in the tops.

 

 

 

 

 

 

photo, removing heated cans with tongs
After the can has filled with steam, it is quickly immersed in a container of ice water.

Click on the small picture to see the video. The file will open in a new browser window.

small photo, immersion of can in ice bath

Video for Windows

small photo, immersion of can in ice bath

Quicktime

The steam is cooled in the ice water and condenses to a small quantity of liquid water. Condensation of steam to liquid water creates a vacuum inside the can. Atmospheric pressure outside the can is around 760 mm Hg, while pressure inside the can is much less. The can collapses because of the pressure difference.

Return to Lecture Demos page