Kinetics and mechanism of ruthenium(III) chloride catalyzed oxidation of phosphorous acid by peroxomonosulfate in acetate buffers

The kinetics of oxidation of phosphorous acid by peroxomonosulfate in acetate buffers in the presence of ruthenium(III) chloride has been studied. The rate of disappearance of the peracid in the reaction has been observedto be zero order with respect to peroxomonosulfate. The proposed mechanism conforms to the rate law, -d[PMS] = k' = kK d ‖H 3 PO 3 ‖‖Ru I I I ‖‖H + ‖ - 1 where *'is zero order rate constant. Thermodynamic parameters such as energy and entropy of activation have been calculated by conventional methods.