Compound [$\mathrm{X}$] is obtained on benzene react with ${\mathrm{Cl}}_2$ in presence of ${\mathrm{FeCl}}_3$ . Compound [$\mathrm{Y}$] is obtained on mixing compound [$\mathrm{X}$] with sodium in presence of dry ether. Write the names of compounds [$\mathrm{X}$] and [$\mathrm{Y}$] and write equations of chemical reactions involved.