The Department of Chemistry at the University of Illinois
The Chemistry learning center
Collapsing Can
Why does a Coke can filled with steam collapse in cold water?
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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. |
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After
the can has filled with steam, it is quickly immersed in a container
of ice water. |
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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. |
