Effect of Solvent Changes on Ionization Equilibrium

On the basis of classical electrostatic theory, a large part of the free energy of a pair of ions depends on the dielectric constant of the medium. In a solvent of high dielectric constant, a charged object creates oriented solvent dipoles by polarization or orients existing 

Unfortunately, the available data are neither reliable nor extensive enough to test all of these predictions for carbonium ionization equilibrium. The reason for the inadequacy of the data is the relative scarcity of ionizing solvents that do not react irreversibly with the ions, and the fact that much of the data consists merely of observations of the color of solutions in various solvents. As we have seen, the color may or may not parallel the ionization. 

Gurney, Ionic Processes in Solution, McGraw-Hill, New York, 1953. 

Pearson, Abstracts,. 126th Meeting Am.Chem.Soc.,Sept. 1954,p. 24R. 

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