Chemical Potentials of Components of Binary Nonideal Solutions of Nonelectrolytes

Abstract

The chapter mentions new expressions of the chemical potentials of the components of the binary nonideal solutions of nonelectrolytes. According to the foregoing considerations, it is logic to conceive that the comparison of the chemical potentials of components of ideal solutions with those of the components of nonideal ones may permit to get some insights into the expressions of activities and activity coefficients.

For the sake of further comparisons are set up, here, the expressions of the chemical potentials of the components of a nonideal solution, the behaviors of which are slightly different from that of a perfect solution on one hand and from that of an insufficiently dilute solution, on the other.

The reasoning leading to the expressions being searched for results from a mathematical relation stemming from Kirkwood–Buff’s theory. This relation is recalled. According to it, the derivative at constant temperature and pressures of the chemical potential of a component of the solution with respect to its molar fraction is a function of its molar fraction, of the concentration of the other component and of a new parameter Δ_AB which is a linear combination of the Kirkwood–Buff’s integrals G _AA, G _BB, and G _AB, where A and B symbolize the two components in interaction. When they are possible, the integrations of the foregoing derivative and of its variations (according to the experimental conditions) show the importance of this parameter.