The kinetics of uncatalyzed sodium sulfite oxidation

The influence of pH, oxygen partial pressure, and sulfite conversion on the reaction rate of uncatalyzed sodium sulfite oxidation is determined experimentally at a temperature of 20-degrees-C. In addition to these experiments, the change in composition of the sulfite solutions during the reaction was estimated on the basis of equilibrium and activity constants. A comparison between the outcome of these calculations and the experimental results shows that the sulfite oxidation mechanism depends on the bisulfite concentration. Furthermore, it is argued that uncatalyzed sulfite oxidation is to be recommended as a model reaction for mass transfer studies as an alternative to cobalt-catalyzed sulfite oxidation at low cobalt catalyst concentrations.