The standard reduction potentials of `Cu^(2+)//Cu` and `Cu^(2+)//Cu^(+)` are 0.337 V and 0.153V respectively. The standard electrode potential of `Cu^(+)//Cu` half-cell is

Options

A. 0.184 V
B. 0.827 V
C. 0.521 V
D. 0.490 V

Answer

C

Explanation

(i) `Cu^(2+) + 2e^(-) to Cu`
`DeltaG_(1)^(@) =-nFE_(1)^(@)=-2Fxx0.337`
(ii) `Cu^(2+) +e^(-) to Cu^(+)`
`DeltaG_(2)^(@) =-nFE_(2)^(@) =-1Fxx0.153`
Substracting eq (ii) from (i) , we get
`Cu^(+) + e^(-) to Cu, DeltaG^(@) =DeltaG_(1)^(@) -DeltaG_(2)^(@)`
`=-2Fxx0.337 -(-1Fxx0.153)`
`=-0.674 F+0.153 F=-0.521 F`
`E_(@)=(-DeltaG)/(nF)=(0.521 F)/(1xxF)=0.521 V`