Which of the following reactions are disproportionation reaction ?

Options

A. `Cu^(+) rarr Cu^(2+) + Cu`
B. `3MnO_(4)^(-) + 4H^(+) rarr 2MnO_(4)^(-) + MnO_(2)+ 2H_(2)O`
C. `2KMnO_(4) +rarr K_(2)MnO_(4) + 2H_(2)O`
D. `2MnO_(4)^(-) + 3Mn^(2+) + 2H_(2)O rarr 5MnO_(2) + 4H^(+)`

Answer

a:b

Explanation

In (i) , `Cu^(+)` is oxidized as well as reduced. In (ii) , `MnO_(4)^(-)` ions are oxidised as well as reduced.