The `Mn^(3+)` ion is unstable in solution and undergoes disproportionation reaction to give `Mn^(+2), MnO_(2)`, and `H^(o+)` ion. Write a balanced ionic equation for the reaction.

Explanation

The skeletal equation is `Mn^(3+)+(aq)rarrMn^(2+)(aq)+MnO_(2)(s)+H^(+)(aq)`
Oxidation half equation `overset(+3)Mn^(3+)(aq)rarr overset(3+)(aq)rarr MnO_(2)(s)+4H^(+)(aq)+e^(-)`
balance O atoms by adding `2H_(2)O : overset(2+)Mn^(3+)rarr Mn^(2+)`
balance O.N by adding electrons `Mn^(3+)(aq)^(-)rarrMn^(2+)(aq)`
adding Eq (i) and Eq (ii) the balanced equation for the disportionation reaction is
`2Mn^(3+)(aq)+2H_(2)O(l)rarrMnO_(2)(s)+4H^(+)(aq)+e^(-)`
balance O atoms by adding `2H_(2)Mn(aq)+2H_(2)O(l)rarrMnO_(2)(s)+4H^(+)(aq)+e^(-)`
reduction half equation `overset(+3)Mn^(3+)rarr overset(Mn^(2+)`
lt balance O.N by adding electron `Mn^(3+) (aq)+e^(-)rarrMn^(2+)(aq)` adding eq (i) and eq (ii) the balanced equation for disproportion reaction is
`2 Mn^(3+)(aq)+2H_(2)O+2H_(2)O(l)rarrMnO_(2)(s)+Mn^(2+)(aq)+4H^(+)(aq)`