Titrations in non-aqueous media. Part XVI. Redoximetric titrations of hydrazine and some hydrazine derivatives with manganese(III) acetate in glacial acetic acid

Abstract

Hydrazine hydrochloride and some hydrazine derivatives were titrated potentiometrically with manganese(III) acetate in glacial acetic acid. The titrations were carried out both directly and indirectly. As the direct titrations are very time consuming, the indirect titrations were found to be more practical. The number of electrons exchanged during the reaction in glacial acetic acid is different from the number exchanged if the titration is performed in aqueous media. Hydrazine, phenylhydrazine, 1,2-diphenylhydrazine, diphenylcarbazone and semicarbazide all undergo a two-electron redox reaction with manganese(III) acetate in glacial acetic acid. 4-Nitrophenylhydrazine and 2,4-dinitrophenylhydrazine undergo a redox reaction by releasing one electron under the same conditions. Diphenylcarbazide undergoes a four-electron redox reaction. The results of the acidimetric titration of hydrazine, phenylhydrazine, 4-nitrophenylhydrazine and 2,4-dinitrophenylhydrazine indirectly support the results of the redox titration of these four compounds.