Question

What happens when a nickel rod is dipped into a copper sulphate solution? Justify your answer.

[\[\ce{E{^{\circ}_{Ni^{+2}/Ni}}}\] = − 0.25 V and \[\ce{E{^{\circ}_{Cu^{+2}/Cu}}}\] = +0.34 V]

Answer 1

Since \[\ce{E{^{\circ}_{Ni^{+2}/Ni}}}\] = − 0.25 V is less than \[\ce{E{^{\circ}_{Cu^{+2}/Cu}}}\] = +0.34 V. So Ni displaces Cu²⁺ ions from the solution, and red copper metal starts precipitating.

\[\ce{\underset{Metal}{Ni} + Cu{^{2+}_{(aq)}} -> Ni{^{2+}_{(aq)}} + \underset{Metal}{Cu}}\]