Reaction between alkali metal ferrocyanides and persulfates in aqueous solution

Abstract

The rates of the reaction of ferrocyanide and persulfate ions, in the presence of various concentrations of different alkali metal cations, have been measured at various temperatures and ionic strengths. The results are interpreted in terms of ion pairs and support the view that the actual reacting species are MFe(CN)6−3 and MS2O8−, where M is an alkali metal. This is similar to the situation found earlier for potassium salts of these ions. The rate constants obtained on this assumption increase gradually from lithium to cesium. Values are also obtained for the apparent activation energies of these reactions.