The standard reduction potential of `Cu^(+)//Cu` couple is 0.34 V at `25^(@)C` calculate the reduction potential at `pH=14` for this couple.
(Given `K_(sp),Cu(OH)_(2)=1.0xx10^(-19)`)

Options

A. `-0.22` V
B. `+0.22` V
C. `-0.34` V
D. `+0.34` V

Answer

A

Explanation

`Cu^(2+) + 2e^(-) to Cu`,
`E = E^(@) - (0.0592)/(2) log_(10) (1)/([Cu^(2+)])`
`= 0.34 - (0.059)/(2) log_(10) ((1)/(10^(-19)))= - 0.22V`.