"Fred Bloggs" wrote in
message ...
Larry Brasfield wrote:
"John Fields" wrote in message ...

Since this a technical forum and we _do_ have ground rules, I believe
we generally agree that, unless otherwise specified, standard pressure
is defined as 760 millimeters of mercury and standard temperature is
defined as zero degrees celcius.


I believe that in this forum we assume temperature is a
variable that must be accommodated in design, unless
otherwise stated. I cannot imagine why any unstated
temperature would be assumed to be 0 oC. I suppose
sea-level atmospheric pressure is often assumed, but
where it matters, it should not be assumed at all.


While the boiling point of water is dependent on pressure, the
freezing point, I believe, is not.


You might want to consider the "triple point" of water,
below which pressure "melting point" is meaningless and
the "freezing point" varies considerably with pressure.


At least, not to a great extent. I don't have any data to support
that position, but I'd love to see some, if it's out there.


See: http://www.lsbu.ac.uk/water/phase.html


Using the usual meaning of "freezing" which is the transition from liquid to solid, that graph shows "freezing" occurring at 273K
over a million to one range in pressure.

It does not. The straight part of the liquid/solid phase
boundary covers less than 5 orders of magnitude. "Over a
million to one" would be more than 6 orders of magnitude.

I would say that the statement "While the boiling point of water is dependent on pressure, the freezing point, I believe, is not"
is essentially true

In a discussion that has involved sublimation, to exclude
that part of the phase space would be essentially silly.

- to all except a nitwit like you.

Off your meds again, Fred? I expect you to be more
careful with your graph reading before breaking into
your frothing-at-the-mouth modes.

--
--Larry Brasfield
email:
Above views may belong only to me.