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"CONTRIBUTIONS TO THERMODYNAMICS: THE INCONSISTENCY OF THERMODYNAMICS," BY 1. McQUIRG DONALD G . MILLER' ELLEN MOCHELI
THIStime it is clear that entropy has really set in with Dr. McQuirg. His argument breaks down at the assertion that the process is isobaric, since the initial and final pressures are 10 and 1 atm., respectively. The actual process is the following: The gas goes instantaneously from an applied pressure of 10 atm. to one of 1 atm. a t constant volume, and then it expands to 10 liters against the constant 1 atm. pressure. The work done by a system on its surroundings is given by
where p, is the pressure applied to the system by the
' Present address: Chemistry Department, University of California Radiation Laboratory, Livermore, California. "resent address: Corning Glass Works, Corning, New York.
s u ~ o u n d i n g s . ~Since the above process takes place in two steps, w = Sp,dV step 1
+f
p,dV. step 2
In step 1, d V = 0, and the first integral vanishes. In step 2, V changes from 1 to 10 liters with p, constant a t 1 atm. Thus the expression for the work becomes
which happens to coincide with McQuirg's incomplete analysis. Since the process is not isobaric, AH Z q. Therefore the alleged inconsistency does not arise after all. This point has been discussed very clearly by J. K. O'LOANE, J. CHEM.EDUC., 30, 190 (1953).
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