Manganimetry in Strongly Alkaline Medium

In strongly alkaline medium, the reduction of permanganate ions into manganese dioxide takes place in two consecutive steps  

the reduction into manganate ions. This step is fast  

the reduction of manganate ions into manganese dioxide. This step is slow  

From the experimental point of view, we operate with an excess of potassium permanganate. After reaction, it is back-titrated with a sodium formiate solution  

The equivalence point is indicated by the complete disappearance of the color. The potassium permanganate equivalent is its molar mass  

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