Consider the following sequence of reactions. Assuming that the reaction proceeds to completion, then $137 \ mg$ of $4-$nitrotoluene will produce . . . . . . $mg$ of $B$. (Given molar mass in $g \ mol^{-1}: H = 1, C = 12, N = 14, O = 16, Br = 80$)

$A$ 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 $(2)$.

Write the chemical reactions for the following conversions:
$1.$ Aniline to Picric acid
$2.$ Ethanal to Butan$-2-$ol

The number of primary,secondary,and tertiary amines possible with the molecular formula $C_3H_9N$ is:

You have been given four bottles marked $A, B, C$ and $D$ each containing one of the organic compounds given below:

$I: C_6H_5CH_2NH_2$	$II: C_6H_5CH_2COOH$
$III: C_6H_5CH_2CH_3$	$IV: C_6H_5CH_2CH(NH_2)COOH$

The following observations were made:
$(i)$ The compound in bottle $A$ did not dissolve in either $1 \ N \ NaOH$ or $1 \ N \ HCl$.
$(ii)$ The compound in bottle $B$ dissolved in $1 \ N \ NaOH$ but not in $1 \ N \ HCl$.
$(iii)$ The compound in bottle $C$ dissolved in both $1 \ N \ NaOH$ and $1 \ N \ HCl$.
$(iv)$ The compound in bottle $D$ did not dissolve in $1 \ N \ NaOH$ but dissolved in $1 \ N \ HCl$.
$(a)$ Indicate the compounds in: bottle $A = \dots$,bottle $B = \dots$,bottle $C = \dots$ and bottle $D = \dots$.
$(b)$ The compound with the highest solubility in distilled water is .......

In a reaction of aniline,a coloured product $C$ was obtained as shown below:
$A$ $\xrightarrow{NaNO_2/HCl} B$ $\xrightarrow{N,N-dimethylaniline, \text{cold}} C$
The structure of $C$ would be: