Abstract
An equation was derived from the Donnan theory on the equilibrium state in which two phases of electrolyte solution are in contact through a membrane or a boundary surface, with the presence of a fixed charge in one (M phase) and not in the other (B phase), and this equation was solved for electrolyte solutions under various conditions. Systematic calculations were made on the effect of charge density of the fixed charge in the M phase, and valency of ions in the electrolytes, volume fraction of the M phase, and binding nature of the fixed charge and ions on the distribution of ionic concentration in the M phase and B phase, and on the Donnan potential between the two phases. Examinations were also made on the relationship between the Donnan equilibrium and apparent binding rate of the ions and the fixed charge obtained by the dialysis equilibrium method. Guntelberg's approximation formula, based on Debye-Huckel's theoretical formula, was used for the activity coefficient of the ions and it was concluded that, according to the result of this calculation, the effect of activity coefficient is considerable for bivalent and trivalent ions, and that the effect was greater when the electrolyte concentration is lower, rather than when it was higher.
