RE: FW: Isopentane Substitute /making N2 slush

<< Previous Message | Next Message >>
From:jim <>
Content-Type:text/plain; charset="us-ascii"

The trouble with "shorthand" is lack of precision. Boiling cools, does sound 
funny. So I'll try again for anybody I might have confused and for Russ Allison 
in particular:
When boiling water, we add heat (energy) until (at normal pressure) water 
reaches 100 degrees and boils. Additional heat yields not further increase in 
temperature, but the additional energy is released through the boiling action.
Next time somebody asks to boil water, just sit some in a vacuum belljar and 
pump. It soon will boil (water is not very good for a mechanical pump) and it 
has not been heated. Russ - English is imprecise: when you say "boil that 
water, you actually mean "heat that water to boiling point". Boiling cools - I 
am sorry about that fact.

In relation to making nitrogen slush.
Lowering air pressure (evacuating) lowers the boiling point. So liquid nitrogen 
boils vigorously and since little heat is lost the boiling actually cools the 
liquid nitrogen until it reaches its freezing point - nitrogen slush.
Any further complaints to Russ please

Jim Darley
ProSciTech                 Microscopy PLUS
PO Box 111, Thuringowa  QLD  4817  Australia
Ph +61 7 4774 0370  Fax:+61 7 4789 2313
Great microscopy catalogue, 500 Links, MSDS, User Notes

On Monday, May 22, 2000 6:35 PM, RUSS ALLISON [] 
> "Boiling cools" - that's the nicest quote I've heard in a long time,
> Jim.
> Russ Allison,
> Dental School
> Cardiff
> Wales

<< Previous Message | Next Message >>