Collect. Czech. Chem. Commun. 1983, 48, 192-198

Excess entropy of the systems of molecules differing in size and shape

Tomáš Boublík

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6


The excess entropy of mixing of mixtures of hard spheres and spherocylinders is determined from an equation of state of hard convex bodies. The obtained dependence of excess entropy on composition was used to find the accuracy of determining ΔSE from relations employed for the correlation and prediction of vapour-liquid equilibrium. Simple rules were proposed for establishing the mean parameter of nonsphericity for mixtures of hard bodies of different shapes allowing to describe the P-V-T behaviour of solutions in terms of the equation of state fo pure substance. The determination of ΔSE by means of these rules is discussed.