A simple theory for the partial molar volumes of a binary mixture

Abstract

A simple theory of mixtures (Snider, N. S. and Herrington, T. M. 1967, J. chem. Phys., 47, 2248) is applied to calculate the excess volumes and excess partial molar volumes of liquid argon—krypton mixtures at T = 134.3 K and several pressures. This theory gives a good qualitative description of these quantities. In particular, the theory gives the correct sign and asymmetry for the excess volumes and partial molar volumes and, at high pressures, non-monotonic curves for the excess partial molar volumes. However, the theory predicts that these effects occur at higher pressures than are seen experimentally. As pointed out before (Hamann, S. D. 1992, High Temp. High Press., 24, 489), such classic theories as regular solution theory and ideal associated mixtures fail to give even the correct sign for these quantities.