The effect of ionic activity and association on the kinetics of ionic reactions. Part I. The estimation of ionic activity coefficients in solutions of constant or varying ionic strength

Abstract

Values of complex ion pair stability constants are reviewed and evidence presented for the existence of perchlorate–complex cation ion pairs. The activity coefficients of 2 : 1, 3 : 1, and 3 : 2 complex ion electrolytes, corrected for ion association, are shown to agree with the Davies equation below an ionic strength of 0·3. Corrected activity co-efficients for six 3 : 1 and fourteen 2 : 1 complex ion electrolytes are tabulated for molar ionic strengths between 0·5 and 4·0. Scatchard's method is used to calculate the activity of these electrolytes in multicomponent mixtures by use of the tabulated data. The effect of activity variation and ionic association on kinetic and equilibrium measurements is considered.