Identify the correct decreasing order of resonance energy per ring for the following compounds: (I) (II) (III)

Step-by-step solution

The resonance energy of benzene (I) is approximately 36 kcal/mol . Since it has one ring, the resonance energy per ring is 36 1 = 36 kcal/mol . The resonance energy of naphthalene (II) is approximately 61 kcal/mol . Since it has two rings, the resonance energy per ring is 61 2 = 30.5 kcal/mol . The resonance energy of anthracene (III) is approximately 84 kcal/mol . Since it has three rings, the resonance energy per ring is 84 3 = 28 kcal/mol . Comparing the values, the decreasing order of resonance energy per ring