Which is the correct basic strength order of the following compounds?

i)

ii)

iii)

iv)

The major product of the following reaction is:

Aniline reacts with mixed acid (conc. ${\mathrm{HNO}}_3$ and conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$ ) at $288\mathrm{ }\mathrm{K} \text{to give} \mathrm{P}\mathrm{ }(51 \%),\mathrm{ }\mathrm{Q}\mathrm{ }\left(47\mathrm{\%}\right) \text{and} \mathrm{R}\mathrm{ }\left(2\mathrm{\%}\right)$ . The major product(s) of the following reaction sequence is (are)

What will be the major product in the following mononitration reaction?

In the reaction sequence

X and Y are, respectively,

The major product obtained in the following reaction is:

The major product formed in the reaction given below will be :