Thermodynamics of phase equilibria

The concept of phase (cpacn appearance ) underlies some of the most remarkable phenomena of thermodynamics, and the complete elucidation of phase equilibrium phenomena represents the most famous achievement of Gibbsian thermodynamics. This chapter describes how the Gibbs principles extend almost effortlessly to such complex multiphase systems. 

Let us begin with a formal definition of thermodynamic phase  

Phase a uniform region of the system, with distinct boundaries 

Each system may be characterized as homogeneous or heterogeneous according to the number of distinct phases, p  

The Gibbsian equilibration principles as developed previously (Chapter 5) apply straightforwardly to heterogeneous as well as homogeneous systems. Consider, for example, the heterogeneous two-phase system of phases a, (3. Extensive properties such 

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THERMODYNAMICS OF PHASE EQUILIBRIA AND SOME SIMPLE CALCULATED PHASE DIAGRAMS... 

Urszula Domahska has been professor. Faculty of Chemistry, Warsaw University of Technology since February 1995. She has been the Head of the Physical Chemistry Division since September 1991 and vice director of the Institute of Fundamental Chemistry (1988-1990). She had long-term scientific visits as visiting professor Laboratoire De Thermodynamique Ft D Analyse Chimique, University of Metz, France University of Turku, Finland Faculty of Science, Department of Chemistry, University of Natal, South Africa Department of Chemical Engineering, Louisiana State University, United States. Her interests have included such areas of physical chemistry as thermodynamics, especially thermodynamics of phase equilibria, VLE, LLE, SLE, high-pressure SLE, separation science, calorimetry, correlation and prediction of physical-chemical properties, and ionic liquids. She is a member of the Polish Chemical Society member of the Polish Association of Calorimetry and Thermal Analysis member of lUPAC Commission on Solubility member of International Association of Chemical Thermodynamics and scientific advisor at the Journal of Chemical Engineering Data. 

The thermodynamics of phase equilibria is reviewed in Chapter 17 and the fundamental thermodynamic differences between conserved and nonconserved order parameters are reinforced with a geometrical construction. These order parameters are used in the kinetic analyses of continuous and discontinuous phase transformations. 

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