What is the major product of the following reaction?
$1,4-dichlorocyclohexa-1,4-diene \xrightarrow{Na, \text{dry ether}} ?$

In the reaction,
$X$ and $Y$ respectively are :-

Identify the position where $E.A.S.$ (Electrophilic Aromatic Substitution) can take place in the given molecule.

Which of the following statements are correct with respect to benzene?
$(i)$ It forms triozonide with $O_3$.
$(ii)$ It is non-planar.
$(iii)$ It forms only one monosubstituted product with $CH_3COCl$ in the presence of anhydrous $AlCl_3$.
$(iv)$ It forms hexachlorobenzene on heating with $Cl_2$ under photochemical conditions.

When benzene is treated with excess of $Cl_2$ in the presence of $FeCl_3$ (or $I_2$ as a carrier),the end product is:

The reaction of toluene with chlorine in the presence of light gives