For the electro-refining of copper, write the reaction that takes place at the anode.

An electrolyte which completely dissociates into ions is:

State one observation for the following:

Copper sulphate solution is electrolysed using copper electrodes.

Arrange the following according to the instructions given in bracket:

${\mathrm{Mg}}^{2+}, {\mathrm{Cu}}^{2+}, {\mathrm{Na}}^{1+}, {\mathrm{H}}^{1+}$ (In the order of preferential discharge at the cathode)

State one relevant reason for the following:

• Graphite anode is preferred to platinum in the electrolysis of molten lead bromide.