Given below are the half -cell reactions
`Mn^(2+)+2e^(-) to Mn, E^(@)=-1.18V`
`Mn^(3+)+e^(-) to Mn^(2+), E^(@)=+1.51 V`
The `E^(@)` for `3Mn^(2+)to Mn+2Mn^(3+)` will be _________.

Options

A. (-)0.33V, The reaction will occur
B. (-2.69V), the reaction will not
C. (-2.69V), the reaction will occur
D. (-.33V), the reaction will not

Explanation

`M n^(2)+2e^(-)to Mn, E^(@)=-1.18V `…..(i)
`2(Mn ^(3+)+e^(-)to Mn^(2+)), E^(@)=+1.51V`…(ii)
Substracting Eq. (ii) From Eq (i), we get
`3M n^(2+)to M n+ 2M n^(3+)`
`E^(@)=-1.18-(+1.51)=-2.69V`
Since, the value og `E^(@)`