Kinetic Theory of Dense-Fluid Mixtures. IV. Square-Well Model Computations

Predictions are given for the viscosity, thermal conductivity, and thermal diffusivity of binary liquid mixtures composed of molecules interacting with a square-well potential. The theoretical formulas were derived by McLaughlin and Davis in Paper I of this series. The viscosity predictions are in good agreement with experiment for binary mixtures of methane, argon, krypton, and xenon liquids. The square-well results are compared with the small-step diffusion theory of viscosity developed by Rice and Allnatt. Thermal diffusivities predicted by the square-well theory are compared to those predicted by the hard-sphere theory. The latter theory predicts values about 25% smaller than those of the former theory. Three equations in McLaughlin and Davis' original work [J. Chem. Phys. 45, 2020 (1966)] contain certain errors. The correct forms of these equations are given in the Appendix.