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The standard reductino potentials E^(c-)...

The standard reductino potentials `E^(c-)` for the half reactinos are as follows`:`
`ZnrarrZn^(2+)+2e^(-)" "E^(c-)=+0.76V`
`FerarrFe^(2+)+2e^(-) " "E^(c-)=0.41V`
The `EMF` for the cell reaction
`Fe^(2+)+Znrarr Zn^(2+)+Fe`
is

A

` -0.35V`

B

`+0.35V`

C

`+1.17V`

D

`0.117V`.

Text Solution

Verified by Experts

The correct Answer is:
B
`E_( Zn^(2+)//Zn)^(@)=-0.76V`
` E_(Fe^(2+)//Fe)^(@)=-0.41V`
`Fe^(2+)+ZnrarrZn^(2+)+Fe`
The two half cell reactions are
`Z nrarrZn^(2+)+2e^(-)`
`Fe^(2+)+2e^(-)rarrFe`
`therefore` Electrochemical cell is
`Zn||Zn^(2+)||Fe^(2+)|Fe`
`E_("cell")^(@)=E_(Fe^(2+)//Fe)^(@)- E_(Zn)^(@)2+_(//Zn)`
`=-0.41V-(-0.76V)=+0.35V`
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