ABSTRACT
This chapter outlines how statistical mechanics has been applied to electrolyte solutions. It concentrates on the physical ideas necessary for understanding liquid solutions, particularly ionic solutions, and how these ideas are reflected in the mathematical formalism. The chapter describes some functions useful for solution theory and for liquid theory in general. It suggests that a complete calculation of the thermodynamic properties of a solution requires knowledge of all interactions, solute-solute, solute-solvent, and solvent-solvent. The chapter discusses them separately at first, with special reference to ionic solutions. It mentions the Monte Carlo method for the direct evaluation of thermodynamic and structural properties. The chapter suggests that the fundamental technical problem of equilibrium statistical mechanics is to evaluate the integral of a rather complicated function over a very high dimensional space: the partition function. It also argues that the McMillan-Mayer theory provides a clear framework for developing approximate calculations of the thermodynamic properties of solutions, and of electrolyte solutions in particular.
