Question

Identify the total number of atoms in product $Q$ in the given sequence of reaction
$C _{6} H _{5} NH _{2} \xrightarrow{ NaNO _{2}+ HCl } X \xrightarrow{ Cu _{2}( CN )_{2}}Y \xrightarrow{ H _{2} O / H ^{+}} Z$

$\xrightarrow{ NaOH / CaO , \Delta}P \xrightarrow{ Cl _{2}, \text { hvExcess }} Q$

Answer 1

$C _{6} H _{5} NH _{2} \xrightarrow{ NaNO _{2} / HCl }C _{6} H _{5} N _{2}^{+} Cl ^{-} \xrightarrow{ Cu _{2}( CN )_{2}} C _{6} H _{5}$
$CN \xrightarrow{ H _{2} O / H ^{+}} C _{6} H _{5} COOH$
$C _{6} H _{5} COOH \xrightarrow{ NaOH / CaO , \Delta}C _{6} H _{6} \xrightarrow{ Cl _{2}, hv \text { (Excess) }} C _{6} H _{6} Cl _{6}$
It is diazotisation reaction to produce $X$, then sandmayer's reaction to give $Y$, followed by hydrolysis to produce benzoic acid $ (Z)$. Benzoic acid on decarboxylation gives benzene, which on excess photochlorination gives benzene hexachloride.