Question

What feature is common to all electophillic substitution reaction?

• A. The atom directly attached to the ring has full or well developed partial positive charge
• B. The atom directly attached to the ring is doubly bonded to oxygen
• C. One or more halogen atoms are present in the group
• D. The group is attached to the ring through a carbon

Answer 1

The correct option is A The atom directly attached to the ring has full or well developed partial positive charge

Electrophilic substitution reaction: In the first step of the reaction, the electron-rich aromatic ring attacks the electrophile A. This step leads to the formation of a positively-charged cyclohexadienyl cation. This is unstable, owing both to the positive charge on the molecule and to the temporary loss of aromaticity. Cyclohexadienyl cation is partially stabilized by resonance, which allows the positive charge to be distributed over three carbon atoms.
So in this reaction atom directly attached to the ring has full or well developed partial positive charge.