Kinetics and mechanism of oxidation of lactic acid by KMnO₄ in H₂SO₄ medium

Abstract

The initial oxidation stages of lactic acid by acid permanganate were investigated. The rate of the induction period was slow and then gradually increased. The kinetics of oxidation were second order, first order with respect to both lactic acid and Mn(VII). The reaction was acid catalyzed. Addition of Mn(II) ions largely increased the rate of the initial stages and decreased the rate of the following stages. The oxidation rate was decreased by the addition of F − or [Formula: see text] ions. The Arrhenius equation was valid for the reaction between 16.5 and 34 °C. Activation parameters were evaluated and a mechanism consistent with the results obtained was proposed.