The product of the following reaction is:

Which one of the following compounds undergoes bromination of its aromatic ring (electrophilic aromatic substitution) at the fastest rate?

In the given reaction $A$ is :- $A$ $\xrightarrow{\text{Reduction}} B$ $\xrightarrow{HNO_2} C_2H_5OH$

Among the following compounds nitrobenzene,benzene,aniline and phenol,the strongest basic behaviour in acid medium is exhibited by

$X \ g$ of ethylamine is subjected to reaction with $NaNO_2 / HCl$ followed by water; evolved dinitrogen gas which occupied $2.24 \ L$ volume at $STP$. $X$ is . . . . . . $\times 10^{-1} \ g$.

The correct order of decreasing basic strength of the following compounds is:
$(I)$ Aniline
$(II)$ $p$-Methoxyaniline
$(III)$ $p$-Nitroaniline
$(IV)$ $m$-Nitroaniline