Oxidation states of manganese and pH

[Moogie]

Hi

I am interested in the change in the stability of the oxidation states of manganese with pH

Mn is a stronger oxidising agent in acid than in base which would lead you to believe that the higher oxidation states of Mn are more stable in alkaline conditions.

Does anyone have a reason why? I couldn't find one

Thanks

 

[Borek]

There is a brown precipitate forming in solutions of permanganate. Have you tried to write reaction equation for the decomposition reaction? What are products of the decomposition?