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

Redox reactions of the complexes with cations in higher oxidation states. V. Kinetic study of the redox reaction of manganese(III) with oxalic acid in the medium of acetic acid

E. Marko and Ľ. Treindl

Department of Physical Chemistry, Faculty of Natural Sciences, Komenský University, 801 00 Bratislava

Abstract:  The kinetics of the redox reaction of manganese(III) with oxalic acid in the medium of 70% acetic acid has been studied. The experimental value of the rate constant (s^-1) decreases nonlinearly with increasing concentration of oxalic acid. In the presence of oxalic acid the absorption maximum of Mn(III) shifts by 31 nm towards shorter wavelengths. The redox reaction involves the formation of some intermediary complexes which are analyzed on the basis of kinetic relationships. The measured value of the activation heat capacity   ΔCp⁼= 167calK^-1 mol^-1 may be in connection with the change in the structure of solvent brought about by the effect of temperature.

Full paper in Portable Document Format: 281a31.pdf

Chemical Papers 28 (1) 31–36 (1974)