Review of heat capacity, enthalpy, entropy and free energy concept, fugacity, activity, activity coefficient and the equilibrium constant, solutions - Raoult's law and Henry law, properties of Raoultian ideal solution, non-ideal solution, binary Gibbs-Duhem equation and its application to activity and activity coefficient determination, study of thermodynamic properties of metallurgical systems with special emphasis on liquid metals and slags, quasichemical theory, excess thermodynamics functions, regular and sub regular models of metallic solutions, interaction parameter and interaction coefficient, ternary Gibbs-Duhem integration, theory of ideal mixing of silicates, tubular representation of thermodynamic data and the free energy function.