$(CH_3)_2CHCONH_2$ $\xrightarrow{Br_2/NaOH} A$ $\xrightarrow{COCl_2} B$. In this reaction sequence,$B$ is:

Which of the following products is $NOT$ obtained when nitrobenzene is reduced in an alkaline medium?

Which of the following substituents,when attached at the para-position of aniline,decreases its basicity?

$A$ student has been given a compound $x$ of molecular formula $C_6H_7N$. $x$ is sparingly soluble in water. However, on addition of dilute mineral acid, $x$ becomes soluble in water. $x$ when treated with $CHCl_3$ and $KOH$ (alc.) produces $y$. $y$ has a specific unpleasant smell. On treatment with benzenesulphonyl chloride, $x$ gives a compound $z$ which is soluble in alkali. The number of different $H$ atoms present in $z$ is:

Identify $X$ and $Y$ in the following reactions:

Which of the following has the highest value of $pK_b$?