The order of stability of aromatic hydrocarbons given below is

Options

A. A lt D lt B lt C
B. D lt Alt B lt C
C. B ltCltDltA
D. Alt D lt B lt C

Answer

D

Explanation

Stability of benzene and polycyclic aromatic compounds is determined by resonance energy per ring. Benzene has resonance energy of 36 kcal/mol per ring, naphthalene has 30.3 kcal/mol, phenanthrene has 30.5 kcal/mol and 1 anthracene has 28 kcal/mol resonance energy per ring. Stability of aromatic compound is directly proportional to resonance energy per ring. Hence, order of stability: Benzene (A) > phenanthrene (D) > naphthalene (B) > anthracene (C)