Abstract
The permanganate ion oxidation of acetanilide was studied spectrophotometrically by measuring the changes in absorbance at 525 nm in perchloric acid solutions. At lower [H+], the formation of an intermediate was observed whereas at higher [H+], the nature of reaction-time curve was sigmoid. The reaction rate increases with [H+] and the kinetics reveals complex order dependence in [H+]. The kinetic data for the oxidation of acetanilide indicate that the mechanism involves two steps. The order in [acetanilide] was found to be one. Water soluble Mn(IV) has been identified as an intermediate in the reduction of MnO4- by acetanilide. The hydrogen ions have been found to decrease the stability of the Mn(IV). Externally added Mn(II) (a product of the reaction) has a composite effect (inhibition and catalysis). The addition of F- in the form of NaF has no effect on the reaction rate. The Arrhenius equation was valid for the reaction between 40 and 60 degrees C. The energy of activation, enthalpy and entropy of activation have been evaluated. Mechanisms consistent with the observed kinetics results have been suggested.