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Given the standard half - cell potential...

Given the standard half - cell potentials `(E^(@))` of the following as :
`Zn rarr Zn^(2+)+2e , E^(@)=+0.76V`
`Fe rarr Fe^(2+)+2e, E^(@)=0.41V`
The the standard EMF of the cell with the reaction
`Fe^(2+)+Zn rarr Zn^(2+)+Fe` is -

A

`-0.35V`

B

`+0.35V`

C

`+1.17V`

D

`-1.17V`

Text Solution

Verified by Experts

The correct Answer is:
B
`Zn^(2+)+2e rarr Zn , E^(0)=-0.76V`
`Fe^(2+)+2erarrFe, E^(0)=-0.41V`
`therefore E_("cell")^(@)=E_(Fe^(2+)|Fe)^(0)-E_(Zn^(2+)|Zn)=-0.41+0.76=0.35V`
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