Identify the meta-directing group from the following.

Identify the correct statements for a ring system to exhibit aromaticity.
$(i)$ It must not be planar.
$(ii)$ It must possess $(4n+2) \pi$-electrons.
$(iii)$ It must be planar.
$(iv)$ It must possess $4n \pi$-electrons.
The correct answer is

Nitrobenzene can be prepared from benzene by using a mixture of conc. $HNO_3$ and conc. $H_2SO_4$. In the nitrating mixture,$HNO_3$ acts as a

The reaction of benzene with isobutylene in the presence of $H_2SO_4$ gives:

Suitable conditions to prepare hexachlorobenzene $(C_6Cl_6)$ from benzene $(C_6H_6)$ is/are:

All the hydrocarbons shown are very weak acids. One,however,is far more acidic than the others. Which one is the strongest acid?