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I was wondering if u can help me find out if water freezes faster with suger in it or just water alone
- Katie (age 7 1/2)
The easy way to test this is to take to similar ice trays of water and dissolve some sugar in one. Let them stand next to each other for a while to get to the same temperature. Then put them in the freezer. See which freezes first. You could try again with the positions switched to make sure they werenít getting different amounts of cooling.
I bet youíll find the plain water freezes first. Dissolving things in water always makes its freezing point lower, i.e. it has to get colder before it starts to freeze. Probably if you leave the trays in for a long time, youíll find that a bit of the sugar water didnít freeze at all. Thatís because the sugar will concentrate in it as the rest freezes, lowering the freezing point even more.
(republished on 07/25/06)
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