Kinetics of oxidation of sodium dithionite by flow thermal method



The homogeneous kinetics and inhibition of sodium dithionite oxidation in an aqueous solution were studied by means of a flow thermal method. Results on the oxidation study of dithionite solutions at 30°C show that the reaction is first order with respect to dithionite and zero order with respect to oxygen. An activation energy of 17.5 kcal/g-mole has been calculated for this reaction. The inhibiting effects of manganese chloride, manganese sulfate, and triethanolamine were inversely proportional to 0.8, 0.9, and 0.2 power, respectively.

A free radical chain mechanism has been proposed, and the rate expressions derived are in good agreement with the experimental data.