If the oxidation potential be defined with reference to `Ag |Ag^(+)` half cell (for which oxidation potential is taken to be zero) , which of the following will give the correct value of oxidation potential of `Cu | Cu^(2+)` half cell (Given that `Cu | Cu^(2+) = -0.34`V and `Ag | Ag^(+) = -0.80` V )

Options

A. `-0.46` volts
B. `-1.14` volts
C. `1.14` volts
D. 0.46 volts

Answer

D

Explanation

For the cell reaction ,
`Cu + 2 Ag ^(+) to Cu^(2+) + 2 Ag`
`E_(cell)^(@) = E_(Ag^(+) |Ag)^(@) - E_(Cu^(2+)|Cu)^(@)`
= `0.80 - 034 = 0.46` V .
This is the difference of reduction potentials of Ag and Cu electrodes . Taking electrode potential of Ag = 0 and `E_(Cu^(2+)| Cu)^(@) = - 0.46` V
or `therefore E_(Cu| Cu^(2+))^(@) = 0.46` V .