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Q & A: more Baloney with salt water

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Most recent answer: 02/08/2011
Q:
http://www.newton.dep.anl.gov/askasci/chem00/chem00361.htm
The question was why an ice cube melted faster in tap water than in salt water. The answer gave reasons why it should melt faster in salt water, and said they explained why it melted faster in tap water.
- Mike W (age 61)
A:
This Baloney comes from a site which has a number of good answers, but which really slipped up on this question.

The key passage in this answer is:
"When you have salty water, the salts in the water make the molar heat of fusion, (and the melting point) lower, and this means that the ice inside this salted water will melt only at a lower temperature. And the ice cubes will melt slowly..."

Of course the explanation given is for why salt makes it easier for ice to melt, lowering the melting point. The person had observed the opposite effect.

We've got several answers explaining the physics of why under common conditions ice cubes melt more slowly in salt water even though it lowers their melting point. Here's one:

Mike W.

(published on 02/08/2011)

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