Given that `E_(Fe^(3+)|Fe)^(0)` and `E_(Fe^(2+)|Fe)^(0)` are `-36V` and `-0.439V`, respectively . The value of `E_(Fe^(3+),Fe^(2+)|Pt)^(0)` would be

Options

A. `(-0.36-0.439)V`
B. `(-0.36+0.439)V`
C. `[3(-0.36)+2(-0.439)]V`
D. `[3(-0.36)-2(-0.439)]V`

Answer

4

Explanation

`nFE_(Fe^(3+)//Fe)^(@)=nEF_(Fe^(3+)//Fe^(2+))^(@)+nEF_(Fe^(2+)//Fe)^(@)`
`3xx(-0.36)=1xxE_(Fe^(3+)//Fe^(2+))^(@)+2xx(-0.439)`
`E_(Fe^(3+)//Fe^(2+))^(@)=3(-3.6)-2xx(-0.439)`