Section 9.14 gives a brief discussion of the ion-interaction model of Pitzer and expressions for the activity coefficient and the osmotic coefficient of binary (single-electrolyte) solutions. This Appendix gives the genera! expressions for these coefficients for multielectrolyte solutions. Also given are tables that list the ion-interaction parameters and their temperature dependence for several common aqueous electrolytes.
For an electrolyte solution containing ws kg of solvent s and solutes i, j,… with molalities mi, mj,…, Pitzer (1995) assumed that the excess Gibbs energy is
Function f(I) depends on ionic strength ...