Theoretical thermodynamic functions for argon gas

Publisher Website
Google Scholar
Abstract
Theoretical thermodynamic functions are computed for argon gas assuming a pair‐potential function of the Lennard‐Jones 6‐12 form. A parametric integral equation is used to obtain radial distribution functions which are then used to obtain the pressure and internal energy. The entropy, enthalpy, heat capacity at constant volume, Helmholtz function, and Gibbs function are then obtained as functions of temperature and density. The parameter in the integral equation is obtained by requiring agreement in the theoretical and experimental pressures at high density. The theoretical computations are compared with experimental results for a range of temperatures from 0 to 150 °C and for densities up to 640 amagat (pressures to 2900 atm). The agreement between experiment and theory is reasonably good; however, some differences indicate that improvement might be obtained using a different pair‐potential function.