Molecular Thermodynamics of Fluid-Phase Equilibria

Appendix H Brief Introduction to Perturbation Theory of Dense Fluids

Statistical mechanics provides a powerful tool for representing the equilibrium properties of pure and mixed fluids because it provides the link between microscopic and macroscopic properties; if we can establish some quantitative relations concerning the properties of a small assembly of molecules, statistical mechanics provides a method for “scaling up” those relations to apply to a very large number of molecules. These scale-up relations can then be compared with ordinary therrnodynamic properties as measured in typical (macroscopic) experiments.

Because we do not have a satisfactory physical understanding of dense fluids, we cannot establish a truly satisfactory theory ...