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Author Topic: Why did a frozen bottle of water contract rather than expand?  (Read 6932 times)

Offline hamza

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i put a plastic bottle full of water in the refrigerator and took it out after it had frozen.. i was wondering why it had compressed by that time. It even compresses after a little while even before freezing to ice. WHAT CAUSES IT TO COMPRESS rather expand.??


[MOD EDIT - TITLE ALTERED TO RE-FORMAT AS A QUESTION.]
« Last Edit: 03/06/2010 00:35:48 by chris »


 

Offline graham.d

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Why did a frozen bottle of water contract rather than expand?
« Reply #1 on: 03/06/2010 08:44:46 »
Water is most dense at 4 degrees Celsius. It get dramatically less dense when frozen at 0C, however does get more dense if the temperature is lowered further, though never getting close to the maximum density at 4C. So, if you put ice in the freezer at around 0C, then cooled it further, it will shrink a little.
 

Offline tommya300

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Why did a frozen bottle of water contract rather than expand?
« Reply #2 on: 03/06/2010 11:47:48 »

If the initial Temperature is higher does this mean the more of a collaps before 4 derees celcius?

I put a plastic bottle full of water in the refrigerator and took it out after it had frozen.. i was wondering why it had compressed by that time. It even compresses after a little while even before freezing to ice. WHAT CAUSES IT TO COMPRESS rather expand.??


[MOD EDIT - TITLE ALTERED TO RE-FORMAT AS A QUESTION.]

Interesting article...

http://www.iapws.org/faq1/freeze.htm

"Water is one of the few exceptions to this behavior. When liquid water is cooled, it contracts like one would expect until a temperature of approximately 4 degrees Celsius is reached. After that, it expands slightly until it reaches the freezing point, and then when it freezes it expands by approximately 9%.

This unusual behavior has its origin in the structure of the water molecule. There is a strong tendency to form a network of hydrogen bonds, where each hydrogen atom is in a line between two oxygen atoms. This hydrogen bonding tendency gets stronger as the temperature gets lower (because there is less thermal energy to shake the hydrogen bonds out of position). The ice structure is completely hydrogen bonded, and these bonds force the crystalline structure to be very "open", as shown in the following picture


In the following two pictures, the first shows a typical structure of liquid water, while the second is an ice structure; note the extra open space in the ice.
 



It is this open solid structure that causes ice to be less dense than liquid water. That is why ice floats on water, for which we should all be thankful because if water behaved "normally" many bodies of water would freeze solid in the winter, killing all the life within them."

« Last Edit: 03/06/2010 12:45:41 by tommya300 »
 

Offline hamza

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Why did a frozen bottle of water contract rather than expand?
« Reply #3 on: 03/06/2010 14:01:47 »
the question remains unanswered ..WHY DOES THE BOTTLE CONTRACT?? even when it has no water in it?
 

Offline graham.d

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Why did a frozen bottle of water contract rather than expand?
« Reply #4 on: 03/06/2010 15:04:59 »
I thought I had answered your question, Hamza. Please be more precise with your question.

Ice will contract as you lower the temperature. It will not contract so much that it achieves the same (smaller) volume of water though. I said this before.

If this does not answer your question, then restate your question clearly. Your last post is asking why the bottle contracts, not its contents. Is that what you mean? If this is so then I suspect you are mistaking the bottle contracting from the ice expanding as you lower the temperature just below freezing.
 

Offline tommya300

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Why did a frozen bottle of water contract rather than expand?
« Reply #5 on: 03/06/2010 17:12:45 »
Hamza since your original question it is safe to say your question does remain answered.
Your second question now is answered too.

the question remains unanswered ..WHY DOES THE BOTTLE CONTRACT?? even when it has no water in it?

Charles's law  Boyle's law
http://www.sciencespot.net/Media/gaslaws.pdf

Ambient temperature Air in a bottle, when sealed, is cooled. I think there is a proportion indirectly proportional relative

 v1/t1=v2/t2 solve for V2

If t2 is smaller then t1, v2 will reduce
if t2 is larger then t2, v2 will increase
« Last Edit: 03/06/2010 17:19:39 by tommya300 »
 

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Why did a frozen bottle of water contract rather than expand?
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