Mohammed, Y.Iyun, J.F.Idris, S.O.2023-12-142023-12-142009-11-09Mohammed Et. el. (2009) Kinetic approach to the mechanism of the redox reaction of malachite green and permanganate ion in aqueous acidic mediumhttps://keffi.nsuk.edu.ng/handle/20.500.14448/5531The redox kinetic and mechanistic studies of the reactions of malachite green (MG+) and MnO4– were carried out in aqueous acidic medium, at a temperature of 32.5 ± 0.5°C; ionic strength, µµµµ = 0.50 mol dm–3 (Na2SO4), [H+] = 5.00 x 10–3 mol dm–3 (H2SO4). In the stoichiometry, one mole of malachite green was consumed by one mole of MnO4–. The reaction is first order in both [MG+] and the [MnO4–]. The rates of redox reaction showed dependence on acid concentrations (in the acid range used). Rate equation for the reaction has been proposed as: –d[MG+]/ dt = (a + b[H+])[MG+][MnO4–]. At [H+] = 5.00 x 10–3 mol dm– 3, the second order rate constant for the malachite green – MnO4– reaction was found to be (11.96 ± 0.13) x 10–3 dm3 mol–1 s–1. The rates of reaction displayed negative salt effect. Log k1 versus 1/D gave positive slope for the reaction. Added anions and cations catalysed the malachite green – MnO4– reaction. Results of the Michaelis- Menten analysis gave no evidence of intermediate complex formation. Based on the results obtained experimentally, the outer sphere mechanism is proposed for the malachite green – MnO4– reaction.enkinetics, mechanism, catalysis, salt effect.Article