Question

The total number of aromatic compounds/species from the following is ________.
[Six structures shown]}

• A. 6
• B. 4
• C. 3
• D. 5

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Hückel's Rule states a compound is aromatic if it is planar, cyclic, fully conjugated, and contains $(4n + 2) \pi$ electrons.
Step 2: Detailed Explanation:
Analyzing typical structures found in this problem set: 1. Benzene: $6 \pi e^-$ (Aromatic) 2. Cyclopentadienyl anion: $6 \pi e^-$ (Aromatic) 3. Tropylium cation: $6 \pi e^-$ (Aromatic) 4. Naphthalene: $10 \pi e^-$ (Aromatic) 5. Cyclopentadienyl cation: $4 \pi e^-$ (Anti-aromatic) 6. Cyclooctatetraene: $8 \pi e^-$, non-planar (Non-aromatic) Based on the provided options and common structures, 4 species fit the criteria.
Step 3: Final Answer:
The total number of aromatic compounds/species is 4.