Thermodynamics of eutectic mixtures. Addition compounds and associated mixtures

Abstract

This paper reviews the earlier studies on thermodynamic and thermochemical properties of eutectic mixtures, addition compounds in the context of the binary mixtures of A and B where possibility of formation of molecular complexes of AB and AB2 type exists. Solid-liquid equilibrium studies along with experimental measurements on phase diagrams and heats of fusion of eutectics (along with micro structure) and molecular complexes have been examined together with experimental results on Associated fluid mixtures related to (i) equilibrium properties such as vapour presure, volume of mixing, heat of mixing and isentropic compressibility and (ii) dielectric and electro-optical properties viz dielectric constant, refractive index and molar polarization. Current status of Ideal Associated Solution Model has been critically discussed in terms of statistical mechanical considerations keeping in view (i) nature of molecular interaction influencing the vibration or rotation of neighbouring molecules and (ii) size effect. Some comments on the nature of stacking of A and B molecules in such complexes has been that complexation is so easy that formation of AB and AB2 complexes can take place even by reaction in the solid state. © 1994, Walter de Gruyter. All rights reserved.