Re: Definitions of Temperature

["Richard W. Tarara" <rtarara@saintmarys.edu>]

Well the well worn 'definition' of temperature to which you object is good
_only_ for ideal gasses but is usually stated as:

"Absolute (Kelvin) temperature is proportional to the AVERAGE,
TRANSLATIONAL, KINETIC ENERGY PER  MOLECULE, due to RANDOM MOTION."

Here all the capitalized words are essential (the translational part takes
care of your vibrational states problem).  What I like about this
description is that it can be derived from first principles (well you do
have to assume the ideal gas law, but all my students are Chem & Bio majors
so they accept the IGL without much question).  At the next level, this
description easily explains the differences between heat capacities of
various gasses based on the number of open channels (translational,
rotational, and vibrational) and the equipartition of energy.  The majority
of  students who receive such instruction in introductory courses never get
to a junior level thermo course where your entropy description can be
effectively taught, but those who do should not have a problem with the
more complete and sophisticated description.

Rick

----------
> From: DSCHROEDER@cc.weber.edu
> Sorry to rant on for so long, but I'm kinda tired of having to teach
> students to unlearn the incorrect definition of temperature as being
> proportional to average kinetic energy.
>
> Dan Schroeder