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| MackTuesday... |
 Posted: Fri Oct 16, 2009 2:34 pm |
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Guest
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My chemistry book gives the following formulation for the Sackur-
Tetrode equation:
S = 3R/2 ln m + 3R/2 ln T + R ln V - R ln N + 5R/2 + 3R/2 ln (2pi k /
h^2)
The partial derivative of S with respect to T is
dS/dT = 3R/2T
which appears to be independent of pressure and volume. Now look at
these formulations for constant-pressure heat capacity and constant-
volume heat capacity:
Cp = T (dS/dT)_P
Cv = T (dS/dT)_V
Here "_P" and "_V" refer to values of dS/dT at constant pressure and
volume, respectively. I have two questions. How is the Sackur-Tetrode
equation reconciled with the fact that Cp does not equal Cv, and what
causes the difference between Cp and Cv? |
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