Some titrimetric applications of manganese(III) salt solutions: analysis of higher valent complexes of manganese and nickel
Mn2(SO4)3, prepared by oxidising 0.1 M MnSO4 solution in 6 M H2SO4 with 0.02 M KMnO4, was used for titrating solutions of hydrazine or ascorbic acid. The kinetics of dissolution of manganese dioxide in ascorbic acid solution were followed by titration against Mn2(SO4)3 solution. MnIII, NiIII or MnIII+ MnIV were determined in prepared solids by adding a known excess of ascorbic acid solution, which reduces the metal to the divalent state, and back-titrating with Mn2(SO4)3 solution. Although the latter solution can be successfully used for titrating H2O2 or FeII, even in the presence of high concentrations of chlorides, it is not recommended for titrating nitrites or lower vanadium compounds.