On Sun, 21 Dec 2003 00:49:25 -0600, "Tim Williams" wrote:
"Gary Coffman" wrote in message
.. .
It can't. The critical temperature for nitrogen is -232.5 F. Pressure
alone won't keep nitrogen liquid above the critical temperature.

Hmmm... why?

Because that's what the definition of critical temperature for gases
means. Basically, the intermolecular forces between nitrogen molecules
(due primarily to asymmetric charge distribution in the individual
molecules) aren't that strong. That's because of the particular electronic
structure of the nitrogen atom and the particular covalent bond angle of
the diatomic molecule.

The magnitude of the forces trying to break those weak intermolecular
bonds increases with temperature. Shoving them closer together with
pressure isn't enough, above the critical temperature, to get them to
stay in the liquid state because the pressure alone can't compensate
for thermal agitation, ie the force vectors don't line up in opposition
often enough to cancel out throughout the bulk of the material.

Gary