Unlike interactions and binary diffusion in polar-nonpolar mixtures; kryptonmethylene chloride and kryptonethylchloride

Abstract

Binary diffusion coefficients of gases having one polar constituent have been measured in the temperature range 275 to 318°K using the two-bulb technique of Ney and Armistead. The systems investigated were Kr-CH₂Cl₂ and Kr-C₂H₅Cl. Radioactive ⁸⁵Kr was used as a tracer and a scintillation counter was employed to determine its concentration at different times. The mass correction was applied to get the normal diffusion coefficients for both the systems. The experimental D₁₂ values have been employed to get the unlike interaction parameters on the Lennard-Jones (12:6) potential and compared with those obtained by using the combination rules for a polar-nonpolar system and the force constants of the polar gas from viscosity as well as from second virial data. The off-centre model of Blanks and Prausnitz is discussed in detail.