Product $D$ is:-

The product $(A)$ of the given reaction is:

Primary and secondary amines can be distinguished by $:-$

Arrange the following:
$(i)$ In decreasing order of the $pK_{b}$ values:
$C_{2}H_{5}NH_{2}, C_{6}H_{5}NHCH_{3}, (C_{2}H_{5})_{2}NH$ and $C_{6}H_{5}NH_{2}$
$(ii)$ In increasing order of basic strength:
$C_{6}H_{5}NH_{2}, C_{6}H_{5}N(CH_{3})_{2}, (C_{2}H_{5})_{2}NH$ and $CH_{3}NH_{2}$
$(iii)$ In increasing order of basic strength:
$(a)$ Aniline,$p-$nitroaniline and $p-$toluidine
$(b)$ $C_{6}H_{5}NH_{2}, C_{6}H_{5}NHCH_{3}, C_{6}H_{5}CH_{2}NH_{2}$
$(iv)$ In decreasing order of basic strength in gas phase:
$C_{2}H_{5}NH_{2}, (C_{2}H_{5})_{2}NH, (C_{2}H_{5})_{3}N$ and $NH_{3}$
$(v)$ In increasing order of boiling point:
$C_{2}H_{5}OH, (CH_{3})_{2}NH, C_{2}H_{5}NH_{2}$
$(vi)$ In increasing order of solubility in water:
$C_{6}H_{5}NH_{2}, (C_{2}H_{5})_{2}NH, C_{2}H_{5}NH_{2}$

Benzyl isocyanide can be obtained by:
Choose the correct answer from the options given below:

$A$ trinitro compound,$1,3,5$-tris-($4$-nitrophenyl)benzene,on complete reaction with an excess of $Sn/HCl$ gives a major product,which on treatment with an excess of $NaNO_2/HCl$ at $0^{\circ} C$ provides $P$ as the product. $P$,upon treatment with excess of $H_2O$ at room temperature,gives the product $Q$. Bromination of $Q$ in aqueous medium furnishes the product $R$. The compound $P$ upon treatment with an excess of phenol under basic conditions gives the product $S$.
The molar mass difference between compounds $Q$ and $R$ is $474 \ g \ mol^{-1}$ and between compounds $P$ and $S$ is $172.5 \ g \ mol^{-1}$.
$(1)$ The number of heteroatoms present in one molecule of $R$ is . . . . .
[Use: Molar mass (in $g \ mol^{-1}$): $H=1, C=12, N=14, O=16, Br=80, Cl=35.5$
Atoms other than $C$ and $H$ are considered as heteroatoms]
$(2)$ The total number of carbon atoms and heteroatoms present in one molecule of $S$ . . . . . .
[Use: Molar mass in $g \ mol^{-1}$]: $H=1, C=12, N=14, O=16, Br=80, Cl=35.5$
Atoms other than $C$ and $H$ are considered as heteroatoms
Give the answer for question $(1)$ and $(2)$.