Identify the product $A$ in the following reaction:
Aniline $\xrightarrow{(CH_3CO)_2O / \text{pyridine}} A$

On heating an aliphatic primary amine with chloroform and ethanolic potassium hydroxide,the organic compound formed is:

The major product ($70\%$ to $80\%$) of the reaction between $m$-dinitrobenzene with $NH_4HS$ is

Which of the following compounds is more basic in its aqueous solution?

Arrange the following compounds in their correct order of $pK_b$ values.

Write structures of different isomers corresponding to the molecular formula $C_{3}H_{9}N$. Write $IUPAC$ names of the isomers which will liberate nitrogen gas on treatment with nitrous acid.