The behavior of metanitrobenzoic acid and its reduction products is investigated, as well as the variations occurring in the composition of these oxidizers during electrolytic deposition of tin. It is shown that reduction of metanitrobenzoic acid and the products of its incomplete reduction (azoxy, azo, and hydrazo compounds) occurs at potentials which are more positive than the tin reduction potential, which reduces the current efficiency of the metal. The possibility of increasing the current efficiency of tin by separating the electrode spaces is demonstrated.