Question

Compounds 'A', 'B' and 'C' have the same molecular formula C_7H_8O. Compound 'A' and 'B' liberate hydrogen gas with sodium metal. When treated with sodium hydroxide, compound 'B' alone dissolves. Compound 'C' is inert towards both sodium metal and sodium hydroxide. Compounds 'A', 'B' and 'C" are respectively

• A. Cresol, benzyl alcohol and anisole
• B. Benzyl alcohol, cresol and anisole
• C. Benzyl alcohol, anisole and cresol
• D. Cresol, anisole and benzyl alcohol
• E. Anisole, cresol and benzyl alcohol

Answer 1

Answer: (E)

We are given three compounds A, B, and C with the molecular formula \( C_7H_8O \). Let's analyze their behavior to identify each compound:

• Compound A and Compound B liberate hydrogen gas with sodium metal: This means both compounds contain a hydroxyl group (–OH), indicating they are either alcohols or phenols. 
• Compound B dissolves in sodium hydroxide: This is a property of phenols, which form phenoxide ions in basic solutions. So, B is a phenol.
• Compound C is inert to both sodium metal and sodium hydroxide: This suggests it is neither an alcohol nor a phenol. It is likely an ether, which generally does not react with either.

Now, considering the molecular formula \( C_7H_8O \):

• Compound A is likely benzyl alcohol – reacts with sodium but not with NaOH like phenol.
• Compound B is likely cresol (a methylphenol) – reacts with both sodium and NaOH.
• Compound C is likely anisole (methoxybenzene) – an ether that is unreactive in both tests.

Correct Answer:

Correct Answer: (E) Anisole, cresol and benzyl alcohol