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Ryk
 
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Default Air compressor for hull cleaning

On Tue, 25 Apr 2006 19:50:59 -0500, in message

Richard J Kinch wrote:

Dave writes:

And the significance of this distinction between Chemistry and
thermodynamics is ...


The study of physics involving temperature, pressure, heat, work, etc., is
called "thermodynamics". Chemistry as such does not answer such questions,
although chemists use thermodynamics.

It is kind of like the old quarrel over whether chemistry is a branch of
physics, or physics of chemistry.

In any case, PV = nRT presumes zero heat transfer (denoted Q in
thermodynamics).


Actually PV = nRT is just an equation of state for an ideal gas that
would be equally at home in either a thermo or a chem text book. It
doesn't presume a lack of heat transfer, it simply tells you that if
you increase the temperature by adding heat, then either the volume or
the pressure will increase.

One equation in three variables is not enough to fully describe a
problem.

Ryk


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