The standard electrode potentials (reduction) of `Pt//Fe^(3+),Fe^(+2)` and `Pt//Sn^(4+),Sn^(+2)` are `+0.77V` and `0.15V` respectively at `25^(@)C`. The standard `EMF` of the reaction `Sn^(4+) +2Fe^(2+) rarr Sn^(2+) +2Fe^(3+)` is

Options

A. `-0.62V`
B. `-0.92V`
C. `+0.31V`
D. `0.85V`

Answer

A

Explanation

`E_(cell)impliesE_(Sn^(4+)//Sn^(2+))^(0)+E_(Fe^(2+)//Fe^(3+))^(0)implies0.15-0.77`