Generalized van der Waals theory. II. Quantum effects on the equation of state

Abstract

The light gases deviate markedly from the Law of Corresponding States approximately obeyed by the heavier gases. This is due, at least in part, to the quantization of translational motion at higher densities. This effect has been studied within the framework of a generalized van der Waals model. Each particle is treated as moving within a cubic volume determined by the surrounding particles. Changes to the critical parameters and to the shapes of the coexistence and vapour pressure curves are calculated and compare well with experiment, considering the simplicity of our model.