Aromatic Hydrocarbon

P to Q (Dehydration): The reaction shows compound P treated with H2SO4 and heat (Δ). This is a dehydration reaction, which typically converts an alcohol to an alkene by removing a molecule of water (H2O). Therefore, P is cyclohexanol.

Q to Dialdehyde (Ozonolysis): Compound Q is then treated with ozone (O3) followed by zinc and water (Zn/H2O). This is ozonolysis, a reaction that cleaves alkenes (double bonds) to form carbonyl compounds (aldehydes or ketones). The Zn/H2O is a reducing workup, which prevents the formation of carboxylic acids.
If Q is a cyclohexene, then ozone will add to the double bond, creating two CHO groups at either end of the break point.

Therefore, Q is cyclohexene.

The answer is (A), where P is cyclohexanol and Q is cyclohexene.

Correct Option: (E)
1 = C₆H₅COOH (Benzoic Acid)
2 = C₆H₅CH₂COOH (Phenylacetic Acid)

Explanation:

• Reaction (a): Toluene is oxidized by KMnO₄/KOH to form benzoic acid (C₆H₅COOH). The methyl group (CH₃) is fully oxidized to a carboxylic acid group.
• Reaction (b): Ethylbenzene is oxidized by KMnO₄/KOH to form phenylacetic acid (C₆H₅CH₂COOH). The ethyl group (CH₂CH₃) is partially oxidized to an acetic acid group.
• Matching these products with the options confirms that the correct answer is (E).

In aromatic electrophilic substitution reactions, the electron-donating groups increase the reactivity of the aromatic ring towards electrophiles. Among the options, phenol has the most reactive ring due to the electron-donating effect of the hydroxyl group (-OH).
Thus, the correct answer is (C).