UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
If air in a tire contracts when it is cold outside (according to your web site), why does a can of soda expand in the freezer? Thank you!
Answer 1:

This is a good question. As you point out, according to the ideal gas law (PV=nRT where P=pressure, V=volume, n= amount such as moles, R= the ideal gas constant, and T= absolute temperature) when you cool a gas it contracts; yet, as you also point out, when you put a can of soda in the freezer it expands. This is because when the water in the soda freezes, it expands. Water is a very unique liquid in that unlike most other liquids, the solid phase is less dense than the liquid phase (this is why ice floats). So, when you put a can of soda in the freezer, the water in the soda freezes and expands which causes the can to expand. The reason water expands when you freeze it is because water molecules are tetrahedrally shaped and make up to four hydrogen bonds with the neighboring water molecules (two hydrogen bonds are donated and two are accepted). This forms a network of solid water which is less dense then the liquid phase where in some of the hydrogen bonds have been melted and the water molecules tumble around at a higher average density.



Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use