A cell is prepared by dipping a copper rod in `1 MCuSO_(4)` solution and a nickel rod in `1M NiSO_(4)`. The standard reduction potentials of copper and nickel electrodes are `+0.34 V` and `-0.25 V` respectively.
(i) Which electrode will work as anode and which as cathode?
(ii) What will be the cell reaction?
(iii) How is the cell represented ?
(iv) Calculate the `EMF` of the cell.

Explanation

(i) The nickel elctrode with smaller `E^(@)` value(-0.25V) will as anode while copper electrode with more `E^(@)` value (+0.34V) will work as cathode.
(ii) The cell rection may be written as:
At anode: " " `Ni(s)rarrNi^(s)+(aq)+2e(-)`
At cathode: " "`Cu^(2+)(aq)+2e^(-)rarrCu(s)`
Cell reaction: `Ni(s) +cu^(2)+(aq)rarrNi^(2)+(aq)+Cu(s)`
(iii) The cell may be represented as:
`Ni(s)|Ni^(2)+(aq)||Cu^(2)+(aq)|Cu(s)`
(iv) EMf of cell `(cathode)^(@)=E_(anode)^(@)=(+0.34)-(-0.25)=0.59 V`