दिया है `E_(Fe^(3+)//Fe)^(@)=-0.036V," "E_(Fe^(2+)//Fe)^(@)=-0.439V`
परिवर्तन `Fe^(3+)(aq)+e^(-)toFe^(2+)(aq)` के लिये मानक इलेक्ट्रोड विभव का मान होगा :

Options

A. `-0.072V`
B. `0.385V`
C. `0.770V`
D. `-0.270V`

Explanation

`Fe^(3+)+3etoFe," "E^(@)=-0.036V`
`:.DeltaG_(1)^(@)=-nFE^(@)=-3F(-0.036)=0.108xxF`
`Fe^(2+)+2etoFe," "E^(@)=-0.439V`
`:." "DeltaG_(2)^(@)=-2xxF(-0.439)=0.878xxF`
अब `Fe^(3+)(aq)+etoFe^(2+)(aq),E^(@)=?`
`:.DeltaG_(3)^(@)=-1xxFxxE^(@)`
`becauseDeltaG_(3)^(@)=DeltaG_(1)^(@)-DeltaG_(2)^(@)`
`:.-FxxE^(@)=0.108xxF-0.878xxF=-0.77F`
`:.E^(@)=+0.77V`