Abstract:
The development of recent work has indicated clearly that the deductions from the classical theory of electrolytic dissociation are correct only for weak electrolytes; attempts to apply these formulae to concentrated solutions have not succeeded. Although the ideal laws of solution are approximately true for weak electrolytes, for strong electrolytes some new theory must be found. These conclusions led Lewis (Lewis, Proc. Am. Acad., 43, 259, (1907)) to propose a general investigation, by purely thermodynamical methods, of the activities of strong electrolytes. Collecting the meagre data then available, Lewis (Lewis, J. A. C. S. 34, 1631, (1912)) in 1912, by measurements of E.M.F. solubility in the presence of other salts, and freezing point determinations, demonstrated how activities might be obtained. Since the publication of this paper extensive work, confirming Lewis' conclusions, and providing abundant material for the study of ionic activities, has been carried out.
In its original form the conception of activity is not sufficient to explain all the phenomena of concentrated solutions. The inter-ionic attraction theory due largely to Debye (Debye, "Polar Molecules") and Huckel which has supplied a promising field for investigation of solutions, has developed the general thermodynamical treatment and the study of activity. Any consideration of this development in the study of solution laws, although of great importance and far reaching effect, is quite beyond the scope of this thesis. The discussion will be confined to the determination of activities and their general relations to chemical reactions.
