Question

Identify the final product obtained when a mixture of vapours of phenol and hydrogen is passed over nickel catalyst at 433 K .

• A. Cyclohexanol
• B. Cyclohex-2-en-1-ol
• C. Cyclohexane
• D. Benzene

Hint:

Catalytic hydrogenation of the benzene ring of phenol saturates the ring but keeps the hydroxyl group.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Phenol vapour with hydrogen over a nickel catalyst at 433 K undergoes catalytic hydrogenation of the aromatic ring.

Step 2: Reaction
\(\text{C}_6\text{H}_5\text{OH}+3\text{H}_2\xrightarrow{\text{Ni},\,433\text{ K}}\text{C}_6\text{H}_{11}\text{OH}\)
Three \(\text{H}_2\) molecules add to the ring and the -OH group stays.

Step 3: Name the product
\(\text{C}_6\text{H}_{11}\text{OH}\) is cyclohexanol.

Final Answer:
Phenol is reduced to cyclohexanol. \[ \boxed{\text{(A) }\text{Cyclohexanol}} \]