ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Kinetics of the Oxidation of Tris(oxalato)chromate(III) Ion by Manganese (III) Ions

M. Fico and Ľ. Treindl

Institute of Chemistry, Komenský University, Bratislava 1

Abstract: The kinetics and mechanism of the oxidation of Cr(C₂0₄)₃^3- ions by Mn(III) ions have been studied. The rate equation has the form v = 2k'[Mn(III)] [ Cr(C₂0₄)₃^3-]. The measurements have shown that the rate constant k' is a linear function of the concentration of H₃0⁺ ions. The reaction mechanism is proposed according to which the oxidation of protonized Cr(C₂0₄)₃^3- ions takes place in two parallel steps. Analysis of the results, based on the relationship between the rate constant and concentration of H₃0⁺ ions at various temperatures enables us to determine the values of rate constants and activation parameters for both these steps corresponding to Mn_aq³⁺ and MnOH_aq²⁺ respectively. Either reaction step may very likely be based on a mechanism involving internal spheres.

Full paper in Portable Document Format: 262a103.pdf

Chemical Papers 26 (2) 103–109 (1972)