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Author Topic: What Happens When Water Freezes In A Vacuum ?  (Read 4417 times)

Offline neilep

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What Happens When Water Freezes In A Vacuum ?
« on: 01/10/2007 17:23:33 »
Dearest All !

If I place some water in here


SORRY..I meant in here..


Then gave the jar some vacuum suction joy...would would happen to the water when it freezes ?...would it still expand a bit and have oxygen stuff/bubbles/cracks in it ?



 

Offline daveshorts

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What Happens When Water Freezes In A Vacuum ?
« Reply #1 on: 01/10/2007 18:17:48 »
In the long term it would sublime away to form water vapour and disappear off into the vacuum
 

Offline lightarrow

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What Happens When Water Freezes In A Vacuum ?
« Reply #2 on: 02/10/2007 08:15:39 »

Then gave the jar some vacuum suction joy...would would happen to the water when it freezes ?...would it still expand a bit
Yes.
Quote
and have oxygen stuff/bubbles/cracks in it ?[/b]
Much less (almost nothing). However the problem is that you can't start from liquid water so easily, because in the void liquid water boils very fast, even if it's near 0C; you should freeze it very, very fast.
 

Offline chris

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What Happens When Water Freezes In A Vacuum ?
« Reply #3 on: 09/10/2007 09:02:49 »
This is the basis of lyophilisation or freeze-drying. You make something very cold so that the water turns to ice and then reduce the pressure so that the ice slowly vapourises (sublimes, turning directly from a solid to a gas) leaving behind just the less volatile material that was originally dissolved in the water.

This process is used to produce freeze-dried foods, and also medical and scientific reagents. Heat-sensitive proteins, such as enzymes (e.g. restriction enzymes used in genetic engineering), can be freeze dried to a powder for long term storage. In this form they are much more stable.

Chris
 

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What Happens When Water Freezes In A Vacuum ?
« Reply #3 on: 09/10/2007 09:02:49 »

 

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