ABSTRACT
The thermal behavior of iodine xylenols and cresols redox reactions were investigated aiming to throw light on their mechanisms. Kinetic studies of these redox reactions involve determination of the overall reaction order and the order of the reaction in the presence of excess iodine. It also involves determination of the rate constants and thermodynamic parameters at equal variable concentrations of both reactants, and different temperatures. The overall order of the reaction is determined from half-life times and is found to be 1.5-3.0. The reaction is found to be pseudo first order with respect to the substrate. The thermodynamic parameters E alpha, delta S* and delta H* of activation are calculated at various conditions of reactions. A mechanism for the reaction is suggested by considering the results obtained. The reactions involve oxidation of these phenols by a 2e mechanism, followed by the formation of inner ionic complexes [intermediates] which hydrolyze to give the final products. The thermal behavior of these redox reactions are followed spectrophotometrically at different temperatures. All observations occurring during the reaction course are explained and confirm the proposed mechanisms