Coke physics (ice and pressure)

[LostConjugate]

Funny thing just happened. I left my coke in the freezer, expecting the bottle to be busted I found that it wasn't even frozen at all. Liquid all the way through. Figured it was that new fake sugar chemical, but when I unscrewed the cap it instantly turned to ice.

So I guess you can prevent water from freezing if you have enough pressure on it, by preventing it from expanding it doesn't crystallize.

How cold can you get water in this case without turning it to ice? As cold as you want?

Or does the water stop releasing heat.

 

[kjl]

I don't know if anybody's ever figured out the phase diagram for Coke :) but it sounds like it has the same "backwards" property that water has (that increasing pressure will keep it as a liquid in colder temperatures), which makes sense, since it's mostly water.

and see:
http://en.wikipedia.org/wiki/Properties_of_water

Pressure on the Y scale, temperature on the X scale), we're normally at about 10^5 Pa pressure, showing that the freezing point is normally around 273K, but the freezing point drops lower as the pressure increases.

 

[xxChrisxx]

Without a nucleation point, you can get pure water pretty damn cold before it feezes. -44C iirc.

EDIT: It's -42C
http://en.wikipedia.org/wiki/Nucleation#Examples_of_nucleation

 

[LostConjugate]

Is it possible to get it down to 1 degree Kelvin without freezing? It looks like from the charter there that there is a limit.

 

[DaleSwanson]

http://www1.lsbu.ac.uk/water/phase.html

That has more complete and detailed phase diagrams. They show that the coldest you can get liquid water is about -20C (that ignores the nucleation point as chris pointed out).

It seems soda has about 300kPa, which doesn't seem like it would significantly change the freezing point.
http://hypertextbook.com/facts/2000/SeemaMeraj.shtml

 

[kjl]

It seems soda has about 300kPa, which doesn't seem like it would significantly change the freezing point.
http://hypertextbook.com/facts/2000/SeemaMeraj.shtml

Perhaps some of the coke froze, expanded, and increased the interior pressure enough to lower the freezing point...?

 

[LostConjugate]

I think they pressurize the bottle when they pack it. So there was no way for it to expand in the first place. It was diet so there was no sugar in it, it's basically just flavored water.