The Formation of Sulfate in Water Droplets

Abstract

Previous theoretical studies of the formation of sulfate in the SO2-NH3-liquid H2O system have not considered in a rigorous manner the chemical equilibrium equations, and have failed to provide a satisfactory explanation for the catalytic action of the ammonia. In the present paper the equilibria involved are derived. By assuming that the limiting mechanism in the rate of production of sulfate is the oxidation of the sulfite ion, the observed catalysis of the oxidation by ammonia is explained. The theory also predicts a rate of production of sulfate which is in qualitative agreement with experimental results.