Аннотация:The authors have conducted potentiometric titration of carboxylic cation exchanger (degree of crosslinking 12-16%) in a wide range of changes in solution pH (2-12)and concentratio NaCl (0.01; 0.1; 0.5; 1 M). The maximum ion exchange capacity of the ion exchanger on Na+ (10.100.088 mmol/g of dry weight) was determined, and it did not depend on ionic strength of
the solution. It is shown that in the studied range of NaCl concentrations and pH the process of acid-base balance can be adequately described by the equation of Gregor. The values of the parameters of this equation are calculated, according to which analyzed the
behavior of the carboxylic cation exchanger depending on pH and concentration of background electrolyte. The acidic properties of cation exchanger increased with increasing concentration of NaCl from 0.01 to 0.5 M, but further increase in salt concentration did not affect the ionization constant of carboxyl groups. Keywords: Ionic strength; Ion exchange; Ionization constants; Polyelectrolytes; Acid-base properties.