Thermodynamics of systems with compounds having dystectic melting point

The coexistence of the crystalline substance AB, partially dissociating upo n melting with its melt in the system A-AB was described using a new proced ure which does not assume any hypothetical equilibrium. By fitting the expe rimentally determined phase diagram of the system A-AB with the theoretical temperatures of primary crystallisation an original method for the calcula tion of the characteristic thermodynamic quantities, e.g. the degree of dis sociation of the compound AB in the melt and the dissociation,enthalpy of t he crystalline substance AB was developed. The proposed approach was applie d in numerous systems and the obtained results were compared with those of the volume properties analysis. (C) 1999 Elsevier Science B.V. All rights r eserved.