Abstract
The kinetic results of the reduction of water soluble colloidal manganese dioxide by citric acid in the absence and presence of ionic and non-ionic surfactants are presented. Irrespective of the medium, the reaction is first- and fractional-order, respectively, in [oxidant] and [reductant]. The reduction is accelerated by increase in the concentrations of added Mn(II) and non-ionic Triton X-100 but anionic SDS has no effect. The Arrhenius and Eyring equations were valid for the reaction over a range of temperatures and different activation parameters have been evaluated. A plausible mechanism of the reaction is proposed.