$90 \ g$ of ethylamine on reaction with methyl chloride produces a tertiary amine as the exclusive product. The amount of methyl chloride required is:
$[\text{Given atomic masses in amu}: H=1, C=12, N=14, Cl=35.5]$ (in $g$)

How will you convert:
$(i)$ Ethanoic acid into methanamine
$(ii)$ Hexanenitrile into $1$-aminopentane
$(iii)$ Methanol to ethanoic acid
$(iv)$ Ethanamine into methanamine
$(v)$ Ethanoic acid into propanoic acid
$(vi)$ Methanamine into ethanamine
$(vii)$ Nitromethane into dimethylamine
$(viii)$ Propanoic acid into ethanoic acid?

The product $(C)$ of the following reaction 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 .......

$A$ student has planned to prepare acetanilide from aniline using acetic anhydride. The student has started from $9.3 \ g$ of aniline. However, the student has managed to obtain $11 \ g$ of dry acetanilide. The $\%$ yield of this reaction is $.....$ (in $\%$)

Aniline on treatment with $NaNO_2 / HCl$ at about $0^\circ C$ gives a compound $A$, which on further treatment with $CuCN / KCN$ gives a compound $B$, which when reacts with $H_2 / Ni$ gives a compound $C$. The compound $C$ on reaction with $HNO_2$ gives a compound $D$. The structure of $D$ is: