Abstract
A statistical theory of fluid mixtures is derived which is able to predict the excess enthalpy of binary liquid mixtures accurately from volumetric data. The treatment is a modification of the methodology developed by Flory and coworkers, in which the van der Waals energy-volume relationship is replaced by the more general expression, E=-a/Vm. The exponent m is postulated to be a fundamental property of each liquid component and the value of m for a binary mixture is assumed to be a volume fraction averaged function of the values of m for the individual components. The mixture is treated as being composed of two pseudocomponents whose potential energies and properties are not quite the same as those of the pure components from which they are derived. The theory permits the interaction energy between two like molecules in a mixture to vary with concentration.
