Application of Low-Pressure PVT Data for Determining Parameters of the Lennard-Jones Potential-Energy Function Based On the Second Virial Coefficients Data

摘要

Thermodynamic properties of any pure substance may be determined by theintermolecular forces existing between the molecules of that substance. These forcesusually are expressed in terms of potential-energy functions. In this paper, parameters ofthe Lennard-Jones potential-energy function are calculated for selected molecules by useof the second virial coefficients which are obtained from low-pressure PVT data. Theadvantage of this method is that the potential-energy parameters, which indicate themicroscopic properties of the substance, can be found easily from the macroscopicproperties of that substance, I.e. PVT data. The obtained results have considerableaccuracy for simple, spherically symmetric molecules. Further, by use of the correspondingstatestheory, correlations are made to predict the parameters for other substances, wherethe obtained results have acceptable accuracy for simple molecules and monatomic gases.Keywords: Lennard-Jones potential, second virial coefficients, PVT data, correspondingstatescorrelations.