Applications involving oxidation with KBrO3: I. Rapid potentiometric method for manganese alone or in steel and some ores

A rapid and reliable method is developed for the determination of manganese based on oxidation of the divalent cation with a known excess of KBrO₃ to the tetravalent state. The unreacted oxidant as well as Mn(IV) are then reduced with H₂SO₃ to Br^? and Mn(II). The resulting Br^? is titrated with Ag₂SO₄ using silver metal as the indicator electrode. K₂SO₄ is added to increase sensitivity and establish equilibrium in the vicinity of the end point. Fe(III) when present is also reduced with SO₂ to the divalent state, which can be reoxidized with Br₂. The equivalent amount of bromide is again titrated with Ag₂SO₄. The method provides for the simultaneous determination of Mn and Fe and finds application to some ores and steels.