$A$ mixture containing the following four compounds is extracted with $1 \, M \, HCl$. The compound that goes to the aqueous layer is:
$(I)$ Cyclohexyl methyl sulfide
$(II)$ $N$-methylcyclohexylamine
$(III)$ Methoxycyclohexane
$(IV)$ Cyclohexyl methyl ketone

Identify the major product formed in the following reaction: $C_6H_5NH_2 + CHCl_3 + 3KOH \to ?$

Which reagent is used in the conversion of $C_2H_5NH_2$ to $C_2H_5Cl$?

Compound $III$ is
$\xrightarrow[{ii)\,CuCl/HCl}]{{i)\,HNO_2\,(0 - 5\,^oC)}}I$ $\xrightarrow{{Sn/HCl}}II$ $\xrightarrow[{ii)\,H_3PO_2 + H_2O}]{{i)HNO_2\,(0 - 5\,^oC)\,}}III$

The bad-smelling substance formed by the action of alcoholic caustic potash on chloroform and aniline is:

$A$ hydrocarbon $A$ $(C_{4}H_{8})$ on reaction with $HCl$ gives a compound $B$ $(C_{4}H_{9}Cl)$ which on reaction with $1 \ mol$ of $NH_{3}$ gives compound $C$ $(C_{4}H_{11}N)$. On reacting with $NaNO_{2}$ and $HCl$ followed by treatment with water,compound $C$ yields an optically active compound $D$. The compound $D$ is