Anionic-micelles assisted oxidation of tartaric acid by permanganate: A kinetic and mechanistic approach

Abstract

In this study, we demonstrate the catalytic effects of sodium dodecylbenzenesulphonate (SDBS) on the oxidation of tartaric acid by permanganate. UV–visible spectroscopic data revealed that the reaction proceeds through the formation of a transient species between the reactants. The values of ∆ ε = 12.8 × 105 mol− 1 dm3 cm− 1 and Kc = 6.5 × 10− 4 mol− 1 dm3 were calculated from the kinetic data. Reaction-time profiles show that the reaction has an induction period (slow step) followed by an auto-acceleration path (fast step). SDBS is found to be stable in presence of MnO4−. The reaction follows first-order kinetics with respect to tartaric acid under pseudo-first-order conditions in absence and presence of SDBS. The observed results are discussed in terms of pseudo-phase model of the micelles proposed by Menger and Portony. The values of activation energy = 99 kJ mol− 1 and 59 kJ mol− 1 were calculated by using Arrhenius equation, respectively, in absence and presence of SDBS micelles. The probable mechanisms have also been proposed and discussed. Presence of silver ions also catalyzed of reaction rates.