Question

Which out of the following is aromatic hydrocarbon ?

• A. Cyclobutadiene
• B. Furan
• C. Naphthalene
• D. Pyridine

Answer 1

Answer: (C)

C

Answer 2

Aromatic hydrocarbons must be cyclic, planar, fully conjugated, follow Hückel's (4n+2)π electron rule, and contain only carbon and hydrogen.

(A) Cyclobutadiene has 4π electrons, making it anti-aromatic.

(B) Furan is aromatic (6π electrons) but contains oxygen, so it's not a hydrocarbon.

(C) Naphthalene is cyclic, planar, fully conjugated, has 10π electrons (4n+2, n=2), and contains only carbon and hydrogen. Thus, it is an aromatic hydrocarbon.

(D) Pyridine is aromatic (6π electrons) but contains nitrogen, so it's not a hydrocarbon.