Ion pairing and the rate of the reaction between hexacyanoferrate(II) and octacyanotungstate(V) ions

The rate of the reaction Fe(CN)₆^4–+W(CN)₈^3–Fe(CN)₆^3–+W(CN)₈^4– in aqueous solution has been studied at various temperatures and ionic strengths, in the presence of Group IA cations. The results, combined with earlier work on the ion pairing of these compounds, give an indication of the number of cations present in the activated complex, a number which increases steadily in going from Li⁺ to Cs⁺ as the associated cations. Activation parameters for the reaction at various total [M⁺] are also evaluated.