# Behaviour of liquid in vaccume

Is it possible for a liquid to exist in a high quality vacuume? For example, a few Torr.

If so what are the methods for doing this?

-
 What is "quality" of a vacuum? What makes that quality "high"? – Georg Sep 16 '11 at 9:36 Means good vaccume like outer space. – Zain Sep 16 '11 at 9:40 Aha, and that "outer space" is "a few" Torr? – Georg Sep 16 '11 at 9:43 Assume it 0 or few torr. – Zain Sep 16 '11 at 9:50 Asside: A few Torr is not a particularly good vacuum (only $10^{-3}$ Atm), nuclear and particle physicist use vacuums at or below $10^{-6}$ Atm on a regular basis. – dmckee♦ Sep 16 '11 at 14:59

It's absolutely possible to have stable liquids at low pressures. It all depends on the equilibrium phase diagram of the liquid in question.

Looking at the triple points (a good estimate of the lowest pressure at which the liquid is stable) for a variety of liquids, you can see that mercury for example (it's in this pdf, I promise) has its triple point at -38 C and ~$10^{-6}$ Torr. In other words, liquid mercury is thermodynamically stable near this pressure and temperature and can thus certainly be stable at a pressure of a few Torr.

-