A solution of KMnO4 on reduction yields either a colourless solution or a brown precipitate or a green solution depending on pH of the solution. What different stages of the reduction do these represent and how are they carried out?

NEETprep Answer: Oxidising behaviour of KMnO4 depends on pH of the solution.
In acidic medium (pH < 7)
                             
MnO4-+8H++5e-Mn2++4H2O
Colourless
In alkaline medium (pH > 7)
MnO4-+e-MnO42-
(Green)
In neutral medium (pH = 7)
 
MnO4-+2H2O+3e-MnO2+4OH-
(Brownppt)