THERMODYNAMICS OF EUTECTIC MIXTURES - ADDITION-COMPOUNDS AND ASSOCIATED MIXTURES

This paper reviews the earlier studies on thermodynamic and thermochem ical properties of eutectic mixtures, addition compounds in the contex t of the binary mixtures of A and B where possibility of formation of molecular complexes of AB and AB2 type exists. Solid-liquid equilibriu m studies along with experimental measurements on phase diagrams and h eats of fusion of eutectics (along with micro structure ) and molecula r complexes have been examined together with experimental results on A ssociated fluid mixtures related to (i) equilibrium properties such as vapour presure, volume of mixing, heat of mixing and isentropic compr essibility and (ii) dielectric and electro-optical properties viz diel ectric constant, refractive index and molar polarization.Current statu s of Ideal Associated Solution Model has been critically discussed in terms of statistical mechanical considerations keeping in view (i) nat ure of molecular interaction influencing the vibration or rotation of neighbouring molecules and (ii) size effect.