Question

The standard reduction potential for `Fe^(2+) //Fe` and `Sn^(2+) //Sn` electrodes are `-0.44` and `-0.14 ` volt respectively. For the given cell reaction `Fe^(2+) + Sn rarr Fe + Sn^(2+) `, the standard ` EMF` is.
A. `+.030v`
B. `-0.58v`
C. `+0.58v`
D. `-0.300`

Answer 1

Correct Answer - D
The two half cell reactions are
`SnrarrSn^(2+)+2e^ (-)`
`Fe^(2+)+2e^(-)rarrFe`
`therefore` cell representation is
`Sn|Sn^(2+)||Fe^(2+)|Fe`
`E_("cell")^(@)=E_(Fe^(2+)//Fe)^(@)-E_(Sn^(2+)//Sn)^(@)`
`=-0.44V-(-0.14V)=0.30V`