Re: Dumb Question
- From: Uncle Al <UncleAl0@xxxxxxxxxxxxx>
- Date: Wed, 21 Mar 2007 08:43:12 -0800
EskWIRED@xxxxxxxxxxxxxxxxxxx wrote:
I'm sorry in adance for even asking...
I know that a high pressure environment will raise the boiling point of a
liquid. I have some vauge knowledge of vapor pressure, etc.
The boiling point is that temp at which the liquid's vapor pressure
equals the ambient pressure. Boiling point thus varies with depth of
liquid, leading to interesting BLEVEs when oil storage fires are
fought with water.
But does high pressure also raise the freezing point of a liquid? If not,
do any environmental factors raise the freezing point?
Look at a PVT phase diagram. In general, a liquid that contracts upon
freezing will have its mp raised by pressure (iron in the Earth's
inner core). A liquid that expands upon freezing (water, silicon,
gallium, bismuth) will have its mp lowered by pressure - at least
until a structural phase transition.
I ask because I saw some blurb about freezing water quickly during some
Big Science experiment. The reporter wrote that despite the speed of
freezing, the water was actually quite hot. Indeed, he claimed that the
frozen water was in excess of 212F.
What is the scoop on this?
Water melts at -22 C/29,990 psi. At higher pressures its melting
point rises. A commercial geodynamic (diamond) press can freeze water
above its normal boiling point of 373 K (20,000 atmospheres). mp =
800K at 590,000 atmospheres.
http://www.lsbu.ac.uk/water/images/phase.gif
One then envisions the solution to Pentagon recruitment and training
woes. Recruit and train the meat, then squeeze it on ice at room temp
until needed. Warehouse and stockpile. Pop the pull tabs and there
is your army fresh and ready to go.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
.
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