The rate-determining step for the preparation of nitrobenzene from benzene is:

Give the resonance structures of the $\sigma$-complex formed during the electrophilic aromatic substitution of benzene. Explain the stability of the $\sigma$-complex.

Hydrogenation of naphthalene $(P)$ with excess hydrogen gas stops cleanly at $1, 2, 3, 4-$ tetrahydronaphthalene $(Q).$ What conclusion can be drawn from this experiment?

What will be the major product in the following reaction?

The correct order of reactivity towards the electrophilic substitution of the compounds aniline $(I)$,benzene $(II)$,and nitrobenzene $(III)$ is

The 'middle oil' fraction of coal tar distillation contains