Kinetics and mechanism of electron-transfer reactions Oxidation of dimethyl sulfoxide by chroniium(VI) in acid perchlorate medium

Department of Chemistry, University of Rajasthan, Jaipur-302 004, Rajasthan, India

E-mail : l.p_riya@yahoo.co.in

Manuscript received 22 February 20/1, revised 05 July 20/1, accepted 12 July 2011

Kinetics of oxidation of dimethyl sulfoxide (DMSO) by chromium(VI) has been studied in acid perchlorate medium. The reaction is second order-first order with respect to each reactant. Hydrogen ion dependence is complex. The kinetic rate law is represented by eq. (1).

\(-{2\over 3}{d[{Cr^{VI}}] \over dt}\)={k₁[H+]² + k₂[H+]³}[DSMO][Cr^VI]         (1)

The probable mechanism corresponding to rate law (1) has been suggested. Activation parameters have also been evaluated