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Why does a can of pepsi blow up if it is left in the freezer?
- kevin (age 14)
moanalua HS, hawaii
Pepsi's made up mostly of water. The next most important ingredient is
sugar, and then carbonic acid (which makes carbon dioxide, the "fizz").
Water expands when it freezes (and also the solubility of the carbon
dioxide decreases, but I suspect the water expanding is more important
here). The can doesn't expand when it gets cold -- instead it shrinks.
The volumeof the stuff inside the can tries to go up while the can
tries to shrink, so the pressure builds up until .... BAM! Slushy Pepsi
all over your freezer.
(republished on 07/25/06)
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