Which of the following reactions are disproportionation reactions?
`(A)" " Cu^(+)rarrCu^(2+)+Cu`
`(B)" "3 MnO_(4)^(2-)+4H^(+)rarr2MnO_(4)^(-)+MnO_(2)+2H_(2)O`
`(C )" "2KMnO_(4)rarrK_(2)MnO_(4)+MnO_(2)+O_(2)`
`(D)" "2MnO_(4)^(-)+3Mn^(2+)+2H_(2)O rarr5MnO_(2)+4H^(+)`

Options

A. (i),(iii)
B. (i),(ii),(iiii)
C. (ii),(iii),(iv)
D. (i),(iv)

Answer

B

Explanation

(b) (i) `[overset(+1)(Cu)]^(+) to [overset(+2)(Cu)]^(2+)+ [overset(0)(Cu)]`
(ii) `overset(+6)(3MnO_(4)^(2-))+4H^(+) to overset(+7)(2MnO_(4)^(-))+ overset(+4)(MnO_(2))+2H_(2)O`
(iii) `overset(+7)(2KMnO_(4)) to overset(+6)(K_(2)MnO_(4))+overset(+4)(MnO_(2))+O_(2)`