Handbook of Solvents - George Wypych - ChemTech - Ventech!

540 Y. Y. Fialkov, V. L. Chumak
Figure 9.9. Characteristics of solvate shells in the mixed solvent A-B: a - dependence α = EA/EB on composition
of the mixed solvent; b - dependence of the solvate shell composition, x′ B , on composition xB of the mixed solvent
E-A-B.
Figure 9.10. Selective solvation of NaI in mixed solvent cyanomethane-methanol (a) and DMFA-methanol (b,
curve1), DMFA - cyanomethane (b, curve 2): xB - composition of mixed solvent; xB′ - composition of solvate shell
in molar parts of the second component.
The dependence for K us = 1 is given in Figure 9.9b. As it follows from the analysis of
equation [9.94] and Figure 9.9, the compositions of solvate shell and mixed solvent are different.
A similar approach has been developed for calculation of solvate shell composition
Na + and I - in the mixed solvent formed by the components with close values of permittivity.
Such solvent selection permits us to eliminate the permittivity effect on solvation equilibrium.
Resolvation constants have been determined from the calorimetric study. The composition
of anions solvate complex has been determined from experimental data of electrolyte
Bu 4NI assuming lack of the cation specific solvation. Experimental data are presented in
Figure 9.10.