Chemical Potentials of the Components of Ideal Solutions of Nonelectrolytes

Abstract

The expressions of the chemical potentials of the components of ideal binary solutions of nonelectrolytes are given in this chapter. They result from a reasoning of statistical thermodynamics. These expressions, not yet mentioned in the book, are interesting for the purpose of the study of an activity at least for two reasons. The first one is that they provide an intimate link existing between the chemical potential of a component and its activity. The second reason is, simply, the practical importance of solutions. It must not be forgotten, indeed, that most processes probably occur in solutions.

The study mentioned in the chapter is deliberatively limited to that of the binary ideal solutions of nonelectrolytes. This introductory step may facilitate the following study of the activities and activity coefficients of the components of every solution. As for that of electrolyte solutions, it is deferred to a later chapter because of their particular properties.

A particular stress is laid on the fact that the results mentioned here (stemming from statistical thermodynamics) are in full agreement with the experimental data which are at the origin of the definition of ideal and very dilute solutions in classical thermodynamics. In this chapter, the notion of coupling of a molecule of solute with the remaining solvent molecules and also that of a solvent molecule with the other ones is introduced.