Learn more physics!
Q:
Can you get salt by freezig saltwater
- Douglas F. Seamone (age 12)
Faith Middle School, Ft. Benning G.A.
A:
Douglas -
Yes! This is actually one of the ways that water purification
plants get freshwater from saltwater. If you freeze the saltwater very
slowly, the first part that will start to freeze will be just a few
molecules of plain water. (This is because freshwater freezes at a
higher temperature than saltwater.) Once this has happened, more
molecules of water will stick to the first ones, forming an ice crystal
that gradually gets larger. As the ice crystal grows, the salty part
gets more and more salty (since the water molecules are being taken out
of it). Eventually, the salty part will be so salty that the salt will
start forming crystals of its own. So you get separate crystals of ice
and salt.
-Tamara
(published on 10/22/2007)
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