Transport Properties in Gases (Comparison between Theory and Experiment)

The paper reviews our understanding of the properties of gases and their multicomponent mixtures with particular emphasis on transport properties. The review amounts to a systematic comparison between the results of kinetic theory (Boltzmann and Wang Chang‐Uhlenbeck equations) and the best experimental data.Rather than concentrate on a search for suitable potentials, the paper explores the extent to which the existing body of theory can be put to practical use without an explicit knowledge of the intermolecular force potential for any gas. The organizing principle consists in the formulation of an extended law of corresponding states. This proves to be as accurate as the best measurements of all properties for monatomic gases and for certain properties of the polyatomic gases. Thus, instead of a potential, the formulation presents its empirically determined universal functionals together with suitable scaling factors for pure components and mixtures.