The objective of this course is to cover the other side of thermodynamics. Therefore, this course covers the partial properties, chemical potential, all types of fugacities which form the criteria of equilibrium, the property changes of mixing (heat of solutions, change of volumes), the calculation models of activity coefficient, phi/gamma formula, Gibbs/Duham equation, flash point, azeotrope point calculation and VLE calculations. This course gives the theoretical basic to all thermal separation processes and binary and multi component systems are investigated.