Abstract :

In this paper, the  classical second virial coefficient and the corresponding first quantum correction for Ar gas are calculated in the temperature range 100-3000 K. These calculations are based on the Ar-Ar interaction potential. The Boyle and Joule inversion temperatures are determined. The virial equation of state is constructed using second virial coefficient. Extensive calculations are carried out for the pressure-density-temperature behavior as well as for the total internal energy, entropy and Helmholtz free energy. The compressibility Z is evaluated as a measure of non-ideality of the gas. The deviation from ideality becomes most significant at low temperatures. The results are in good agreement with previous results.