A solution of `KMnO_(4)` 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 ?

Explanation

`KMnO_(4)` behaves in different manner depending upon the pH of the medium.
In acidic medium (pH `lt` 7) , the solution becomes colourless.
`MnO_(4)^(-)(aq)+8H^(+)+5e^(-) to underset("(Colourless)")(Mn^(2+)(aq))+4H_(2)O(aq)`
In neutral medium (pH=7), the solution becomes brown.
`MnO_(4)^(-)(aq)+2H_(2)O +3e^(-) to underset("(Brown)")(MnO_(2)(s))+4OH^(-)(aq)`
In alkaline medium ( pH ` gt` 7), the solution acquires green colour. .
`MnO_(4)^(-)(aq)+e^(-) to MnO_(4)^(2-)(aq)`
For specific chemical reaction.