Association constants for the NaSO4- ion pair in concentrated cesium chloride solutions

Capewell, S.G., Hefter, G. and May, P.M. (1999) Association constants for the NaSO4- ion pair in concentrated cesium chloride solutions. Talanta, 49 (1). pp. 25-30.

Abstract

Values of the association constant, β(NASO4-), for the weak ion-pair formed by sodium and sulfate ions in aqueous solution have been determined at 25°C by high precision sodium ion-selective electrode potentiometry in solutions of ionic strength ranging from 0.50 to 7.00 M in CsCl media and in 1.00 M Me4NCl. The data in CsCl media were fitted to an extended form of the Debye-Huckel equation which yielded log β(NaSO4-)0 = 0.834 ± 0.005 at infinite dilution. Evidence is also presented for the formation of very weak ion-pairs between Cs+ and SO4/2-.