Studies on Mutual Diffusion of Polar-Nonpolar Gas Mixtures

Abstract

The two‐bulb technique of Ney and Armistead was employed for the measurement of the diffusion coefficient of binary mixtures of ammonia with argon and krypton in the temperature range —20° to 60°C. Diffusion was allowed to take place through a precision capillary tube connecting the two diffusion bulbs, and a previously calibrated thermal conductivity analyser was used for analyzing the gas samples at different times. A least‐square method was employed for determining the unlike interaction parameters of the Lennard—Jones (12:6) potential from the experimental D₁₂ values at different temperatures. The combination rules for such systems and the force constants of pure components were also used for calculating the unlike interaction parameters. It has been concluded that the combination rules for polar‐nonpolar interactions are reasonably satisfactory but not sufficiently precise for accurate work.