The effect of ionic activity and association on the kinetics of ionic reactions. Part III. The kinetics and equilibria of sulphate substitution in aquopenta-amminecobalt(III) ions

Abstract

The sulphate ion substitution of aquopenta-amminecobalt(III) in solutions of ionic strengths between 0 and 5 is interpreted quantitatively in terms of a dissociative interchange mechanism involving ion pairs and ion triplets. The rate measurements can be predicted by this mechanism by use of rate and equilibrium constants at zero ionic strength combined with corrections calculated from independent measurements of ionic activity and ion association constants. The equilibrium measurements are consistent with the theory.