(a) Chile salt petre, $NaNO _{3}$ being a electrovalent (ionic) compound gives ions in the aqueous solution, therefore it is a conductor of electricity.
(b) Potash alum, $K _{2} SO _{4} \cdot Al _{2}\left( SO _{4}\right)_{3} \cdot 24 H _{2} O$
when dissolve in water, dissociates into its constituent particles. Due to which it is conducting in nature.
(c) Green vitriol, $FeSO _{4} \cdot 7 H _{2} O$, also gives ions in the aqueous solution, so it is conducting in nature.
(d) Ethyl alcohol, $C _{2} H _{5} OH$ being covalent in nature, does not produce any ion in aqueous solution. Hence, it is non-conducting in nature.