Specific effect of alkali-metal cations on the kinetics of peroxodisulfate–iodide reactions. Influence of approach distance, Gibbs energy of hydration and equivalent ionic conductivity

Abstract

The reaction rate between peroxodisulfate and iodide ions for different alkali-metal iodides have been obtained. The specific effect of alkali-metal cations can be understood by means of several correlations between the rate constant and the approach distance, Gibbs energy of hydration of the cation and the cationic conductivity. The deviation of lithium from linearity in the correlations has been discussed. The logarithm of activation energy is a linear function of the Gibbs energy of hydration of the alkali-metal cation. The model proposed has been tested for the reaction between bromoacetate and thiosulfate.