Can water be compressed so much that it freezes?

[Count Iblis]

Exactly. What we call "frozen water" isn't the only solid form of water, it's just the crystal structure that happens to form at atmospheric pressure. If you compress anything below its supercritical temperature it will eventually become solid (or a glass).

However, are you sure your phase diagram is accurate? IIRC once you pass the supercritical points of temperature and pressure, that is all that exists. I could be wrong and/or my P-chem professor left something out.

The supercritical point is just a point where the line of first order transitions between liquid and vapor ends. The critical point itself is point where there is a second order transition. There the heat capacity diverges with a certain universal critical exponent.

But this has nothing to do with the other phase transitions in the phase diagram.

 

[Bob S]

Sandia Lab has forzen water by compressing it in their Z machine. See
http://www.azom.com/news.asp?newsID=8016
Bob S

 

[barycenter]

Freezing the water requires that the molecules have a chance to crystalize. Crystalizing requires that the molecules have enough elbow room to do so. It's not that water wil NOT freeze under extrreme pressure, it's just that water is very complex. There are actually almost a dozen forms of ice water. Ice I (naturally-formed water-ice) is only one.

QUESTION: Does this hold true for all elements?