Solution

Benzene $+ 6Cl_2 \xrightarrow[dark,\ cold]{Anhydr.\ AlCl_3} C_6Cl_6$ (X, hexachlorobenzene – electrophilic substitution of all six H) Benzene $+ 3Cl_2 \xrightarrow[500K]{UV} C_6H_6Cl_6$ (Y, benzene hexachloride – free-radical addition) Number of chlorine atoms in X and Y are 6 and 6 respectively.

Hydrocarbons in past papers

75 questions from this chapter have appeared across 26 exam years.