Collect. Czech. Chem. Commun. 1981, 46, 1433-1438

A discussion on equations of phase equilibrium between two regular binary phases

Jan Vřešťál

Institute of Physical Metallurgy, Czechoslovak Academy of Sciences, 616 62 Brno


The conditions of the existence of extreme on the concentration dependences of absolute temperature (x are mole fractions) T = Tα(xkα) and T = Tβ(xkβ) denoting equilibrium between two binary regular solutions are generally developed under two assumptions: 1) Free enthalpy change of pure components k = i, j at transition from phase α to β is a linear function of temperature. 2) Concentration dependence of excess free enthalpy (identical with enthalpy) of solutions α and β, respectively, is described in regular model by one concentration and temperature independent parameter for each individual phase.