The reaction of aniline with excess liquid bromine gives $......$.

For the given compounds:
$I$: Pyridine
$II$: Pyrrole
$III$: $3$-Pyrroline
$IV$: Guanidine
The correct statement is:

How can aniline be purified?

$A$ primary aliphatic amine on reaction with nitrous acid in cold $(273 \, K)$ and thereafter raising the temperature of the reaction mixture to room temperature $(298 \, K)$ gives a/an .....

What are $X$ and $Y$ in the following reactions?

The decreasing order of basicity for the following amine compounds is: