Write Nernst equation and find e.m.f of cell `Ni//Ni_((0.01M))^(2+)//Cu_((1M))^(2+)//Cu_()`. Given `E_(Cu^(2+)//Cu)^(@)= 0.34V, E_(Ni^(2+)//Ni)^(@)= -0.22V`

Explanation

At anode, `Ni rarr Ni^(2+) + 2e^(-)`
At cathode,
`ul(Cu^(2+) + 2e^(-) rarr Cu)`
`ul(Ni+ Cu^(2+) rarr Ni^(2+) + Cu)`
Nernst equation,
`E = E^(@)- (0.059)/(2) "log"([Ni^(2+)])/([Cu])`
`=0.56 - (0.059)/(2)"log" (0.01)/(0.01)`
E= 0.56V