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arXiv · 1510.02311

On determining absolute entropy without quantum theory or the Third Law of thermodynamics

Andrew Steane
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Abstract

We employ classical thermodynamics to gain information about absolute entropy, without recourse to statistical methods, quantum mechanics or the Third Law of thermodynamics. The Gibbs-Duhem equation yields various simple methods to determine the absolute entropy of a fluid. We also study the entropy of an ideal gas and the ionization of a plasma in thermal equilibrium. A single measurement of the degree of ionization can be used to determine an unknown constant in the entropy equation, and thus determine the absolute entropy of a gas. It follows from all these examples that the value of entropy at absolute zero temperature does not need to be assigned by postulate, but can be deduced empirically.

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Andrew Steane. 2016-01-25. On determining absolute entropy without quantum theory or the Third Law of thermodynamics. https://doi.org/10.1088/1367-2630%2F18%2F4%2F043022

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