The Temperature Dependence of the Diffusion Coefficients of Ar, CO2, CH₄, CH₃Cl, CH₃Br, and CHCl₂F in Water

Abstract

Diffusion coefficient values are reported over a 0 to 35 °C temperature range for Ar, CO 2 , CH 4 , CH 3 Br, CH 3 Cl, and CHCl 2 F in water. Various empirical theories relating these diffusion coefficient values to the viscosity of water (η) and the size of the diffusing solute molecule are examined. None are found valid though a linear relationship is found to hold between log D and log η for all systems. McLaughlin's hard sphere theory is examined and found in surprisingly good agreement with experiment. It is seen, however, that this theory cannot adequately predict the temperature dependence of the diffusion coefficient of the solute.