The effect of nitrate on the autooxidation of tin(II) in citric acid solutions

Abstract

Autooxidation of tin(II) in citric acid-sodium citrate solutions has been studied and the rate of oxidation was described by a rate law first order in tin(II) concentration. The oxidation is inhibited by relatively small concentrations of nitrate ion though nitrate is not consumed in the reaction. It has been found that during the oxidation of tin(II) to tin(IV) keto-acid breakdown products of citric acid are formed and that their presence is critical in overcoming the inhibiting effect of the nitrate ion.