Intermolecular Potentials of Argon, Methane, and Ethane

Abstract

The viscosities of argon, methane, and ethane are reported over a temperature range from ∼210°K to ∼475°K. In conjunction with second virial coefficient data, the viscosities have been employed to estimate the potential parameters for an Exp:6 potential. For the spherically symmetric molecules a single set of parameters served to reproduce the equilibrium and transport properties with serviceable accuracy. For ethane the procedure failed, and this failure was taken as further evidence for the fundamental inadequacy of the assumptions of central forces and elastic collisions.