The electrophile in the nitration of benzene is

Which is the correct order for the rate of sulphonation of benzene?

What is aromaticity? Explain with suitable examples. State the Huckel rule and explain it with a suitable example. Write the requirements for aromatic character in a compound. Show aromatic structures having $1$,$2$,and $3$ rings with suitable examples.

The compound prepared by a substitution reaction of benzene is

In the following reaction sequence,the major products $A$ and $B$ are:

Which of the following is aromatic?