Determination of the true ion exchange constants and instability (dissociation) constants of their complexes, formed in the phase of the ion exchange resin, according to the dependence of the apparent exchange constants on the degree of coverage of the ion exchange resin

Abstract

1. A method was proposed for finding the true exchange constants of ions (Ktrue) and the dissociation constants (Kdis) of their complexes, formed in the phase of the ion exchange resin, by graphical comparison of the calculated and experimental curves of the dependence of the apparent exchange constants (Kapp) of the investigated ions for the hydrogen ion on the degree of coverage of the ion exchange resin. 2. Tables were compiled and families of calculation curves constructed for the exchange of two ions at any values (Ktrue) and with broad variations of combinations (Kdis) and charges of the ions. As applied to the weakly acid carboxyl cation exchange resin KB-4P-2, the experimental curves for the exchange of alkali ions are in good agreement with the calculated curves, while those for ions of the alkaline earth metals are in satisfactory agreement. 3. The sequences of Ktrue in the series Cs+-Li+ and Ba2+-Mg2+ are close to those on strongly acid cation exchange resins. The numerical values of Ktrue proved to be three to five orders of magnitude greater than Kapp, but below the expected values. 4. The constant Kdis of the hydrogen ion is an order of magnitude greater than for carboxylic acid monomers.