Navigation Tree: Property Consistency: Ideal-gas Entropies

Entropies in the ideal-gas state are available for some compounds in TDE through a local static database containing equation parameters published inThermodynamics of Organic Compounds in the Gas State (Volumes I and II) by M. Frenkel, G. J. Kabo, K. N. Marsh, G. N. Roganov, and R. C. Wilhoit, published by the Thermodynamics Research Center (TRC), College Station: TX. 1994.(ISBN 1-883400-04-X)

Entropies in the ideal-gas state can also be derived through combination of experimental data for condensed-phase entropies (obtained through appropriate integration of condensed phase heat capacities from near T = 0 K), entropies of vaporization (typically derived through temperature derivatives of the vapor or sublimation pressure curve, and densities of the condensed and vapor phases, where vapor phase densities are typically evaluated with estimated second and third virial coefficients. The general approach to the calculation of ideal-gas entropies from experimental property data is given here.

A complete description of the algorithm used in TDE for this consistency check is given in reference TDE 9.

Demonstration of mutual consistency between these independently derived ideal-gas entropies provides increased confidence in the reliability of all properties used in the evaluations.