Question

Among the following, the aromatic compound is

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

According to Huckels rule for aromaticity, the aromatic molecule must be planar, cyclic system having delocalised $(4n+2)$ $\pi$ electrons
where, $n$ is an integer, i.e., $0,1,2,3,....$
Thus, aromatic compounds must have $2,6,10$ or $14\pi$ -electrons. Cyclopropenyl cation
has $2\pi$ -electrons $(n=0)$ , hence it is aromatic compound.