Kinetics of the aqueous manganese(III)+ iron(II) reaction by platinum-electrode polarography

Abstract

The rate equation –d[Fe^II]/dt=k_obs[Fe^II][Mn^III] was established by measurements of the iron(II) diffusion current. For 0.3–15°C in 0.54-3 M HClO₄ the variation of k_obs was consistent with the relation k_obs=(k_o[H⁺]+k₁K_h)/([H⁺]+K_h), where K_h is the manganese(III) hydrolysis constant. Values of k₀ are just less than k₁ as in the comparable oxidation of vanadium(IV). It is concluded from further comparisons of rates that the activated complexes are outer-sphere.