Kinetics of Oxidation of Benzaldehydes by Permanganate in Sulphuric Acid-Acetic Acid Mixture

Department of Chemistry, University College, Kakatiya University, Warangal-506 009 Manuscript received 5 June 1978, revised 29 January 1979, accepted 12 March 1979 The oxidation of substituted benzaldehydes by acid permanganate has been studied in acetic acid-sulphuric acid mixture. The reaction is first order each in the substrate and oxidant. The rate of reaction increases with the increase in sulphuric acid concen­tration and that the order With respect of H+ was unity. The solvent effect has been studied at 30° by various acetic acid contents of the medium at constant sulphuric acid concentration. A linear plot of log k against (D - 1)/(2D+ 1) showed that the reaction is of dipole-dipole nature. The substituent effect showed that electron releasing groups enhance the rate of oxidation while electron withdrawing groups retard the rate