What is formed when chlorobenzene reacts with ammonia in the presence of $Cu_2O$ in xylene at $570 \ K$?

In the reaction shown below,the $o/p$ ratio will be highest when:
$C_6H_5R + HNO_3 \xrightarrow{H_2SO_4} o-\text{nitro-substituted product} + p-\text{nitro-substituted product}$

Why does the presence of a $-NO_2$ group at the $o,p$-positions increase the reactivity of haloarenes towards nucleophilic substitution reactions?

Reaction of aqueous sodium hydroxide on $(i)$ ethyl bromide and $(ii)$ chlorobenzene gives:

Identify $Y$ in the following reaction.

In the given reaction sequence,the conversion of $Y$ to $Z$ is: