Theory of the Specific Heat of Electrolytes.

No molecular theory of the specific heat of liquids has been deduced till now. The considerations given in this paper may be regarded as a first attempt to solve that problem. Most molecular theories of solutions regard the solvent as a continuum, treating only the solute as composed of molecules. In this theory this simplification is made wherever possible. For the treatment of certain phenomena, however, it is too great an idealization, and it is necessary to consider the molecular character of the solvent also. As in the theories of other properties of solutions, only differences between the specific heat of the solution and the pure solvent are calculated. The application of the principles to be deduced, to any dilute solution or liquid mixture does not seem to offer any serious difficulties. It seems possible, that by proceeding logically in this direction we may find the key to the explanation of the specific heat of liquids on the basis of molecular models. We first examine a few cases of un-ionized solutions, drawing certain conclusions therefrom, and then proceed to a general consideration of the so-called strong electrolytes. (The solvent is always supposed to be water.) As shown farther on, the results thus obtained are found to be in very good agreement with the experimental data. Electrolytes are in general distinguished from non-electrolytes by the following characteristics. If n mols of a substance are dissolved in nO mols water, so that n + nO, = 1, then we have this relation for non-electrolytes C > n0C0 (1)