On 24 Sep 2003 00:25:22 GMT, TudorHgh wrote:

Well Carbon Dioxide snow would be first, at a bit below -78.5 deg
C.

Not so.

snip vapour pressure stuff that I don't understand (or prehaps just
don't remember from Physics 25 years ago).

To say that CO2 should condense out below -78.5°C is like saying
that water should condense out at all temperatures below 100°C,
which of course it doesn't, because its partial pressure is much
less than one atmosphere, ...

But doesn't the fact that CO2 doesn't have liquid phase (or if it does
it covers a very small temperature range) have an bearing on this?

Water between 0C and 100C (at normal pressures) is liquid rather than
solid... Water condenses out at sub-zero temperatures in its solid
form, ice. Yes, you can get supercooled water but disturbit and it
instantly freezes.

--
Cheers
Dave. pam is missing e-mail