Give the correct characteristic colours of the products $(\mathrm{P}, \mathrm{Q}, \mathrm{R}, \mathrm{S})$ formed in the following reactions.

A) $\mathrm{NO}+{\mathrm{NO}}_2\stackrel{<250 \mathrm{K}}{⟶}\mathrm{P}$

B) $2{\mathrm{NO}}_2⟷\mathrm{Q}$

C) $\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\stackrel{673 \mathrm{K}}{⟶}\mathrm{R}+\mathrm{PbO}$

D) ${\mathrm{HNO}}_3+{\mathrm{P}}_4{\mathrm{O}}_{10}⟶\mathrm{S}+4{\mathrm{HPO}}_3$

Identify the reactions in which ${\mathrm{N}}_2$ is liberated.

$\left(\mathrm{a}\right)$ ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4+\mathrm{NaOH}⟶$

$\left(\mathrm{b}\right)$ ${\mathrm{NH}}_3+{\mathrm{Cl}}_2⟶$ (excess)

$\left(\mathrm{c}\right)$ ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\stackrel{\mathrm{\Delta }}{⟶}$

$\left(\mathrm{d}\right)$ ${\mathrm{NH}}_4{\mathrm{NO}}_3\stackrel{\mathrm{\Delta }}{⟶}$

$\left(\mathrm{e}\right)$ ${\mathrm{NH}}_4{\mathrm{Cl}}_{\left(\mathrm{aq}\right)}+{\mathrm{NaNO}}_{2\left(\mathrm{aq}\right)}⟶$

What are $\mathrm{X}$ and $\mathrm{Y}$, respectively in the following reactions ?

$\mathrm{Au}+\mathrm{aqua} \mathrm{regia}⟶{\mathrm{AuCl}}_4^{-}+{\mathrm{H}}_2\mathrm{O}+\mathrm{X}$

$\mathrm{Pt}+\mathrm{aqua} \mathrm{regia}⟶{\mathrm{PtCl}}_6^{2-}+{\mathrm{H}}_2\mathrm{O}+\mathrm{Y}$

Assertion (A) : The bond dissociation energy increases from ${\mathrm{F}}_2$ to ${\mathrm{Cl}}_2$ and then decreases to ${\mathrm{I}}_2$

Reason (R) : The low bond energy of fluorine is due to the repulsion between the lone pairs of electrons in two fluorine atoms.
The correct option among the following is