Question

Find total number of aromatic compounds from the given organic molecules.

• A. 3
• B. 4
• C. 5
• D. 6

Answer 1

The Correct Option is B

Step 1: Analyzing the compounds.
Let's evaluate each compound to determine if it is aromatic: - (i): A simple benzene ring with a positive charge. This is aromatic because it has 6 π-electrons (follows Hückel’s rule \(4n+2\) for \(n = 1\)).
- (ii): Benzene with a positive charge. This is aromatic due to the presence of 6 π-electrons.
- (iii): A benzene ring with a -CO group. This is also aromatic as it follows Hückel’s rule, and the carbonyl group does not affect the aromaticity.
- (iv): A fused polycyclic aromatic compound (naphthalene). This is aromatic as it has 10 π-electrons and follows Hückel’s rule for \(n = 2\).
- (v): A bicyclic compound. This is not aromatic due to the lack of conjugation.
- (vi): A polycyclic aromatic hydrocarbon with alternating single and double bonds. This is aromatic as it has 6 π-electrons.

Step 2: Conclusion.
The aromatic compounds are (i), (ii), (iii), and (iv). Therefore, there are 4 aromatic compounds.
Final Answer: 4