Selina ICSE 2019, intext question:

Selina ICSE 2019, intext question: 2. Select he ion in each case, that would get selectively discharged from the aqeuous mixture of the ions listed (a) sot, N0ö and OH- (b) Pb2+, Ag+ and Cu2+

because hydroxide ions has the highest ease of discharge because it gives out electrons most readily (easy to be oxidised) during electrolysis. Half equation for the discharge of hydroxide ions is shown below:

                          4OH^–(aq) ----------> 2H₂O(l) + O₂(g) + 4e^–

(b)  Ag⁺
The more reactive the metal, the least tendency for the metal ions to be preferentially discharged at the cathode.
Hence the ions of less reactive metals like copper and silver will be preferentially discharged.

Regards