Question

Identify 'A' in the following reaction:
\[ \text{C}_6\text{H}_5\text{-CH}_2\text{-Cl} + \text{H}_2\text{Pd-BaSO}_4 \rightarrow \text{C}_6\text{H}_5\text{-CH}_2\text{-CHO} + \text{HCl} \]

• A. Benzoic acid
• B. Benzyl chloride
• C. Benzoyl chloride
• D. Chlorobenzene

Hint:

In reactions with hydrogenation catalysts like Pd/BaSO\(_4\), the benzyl group is oxidized to a carbonyl group (-CHO), forming benzoyl chloride.

Answer 1

The Correct Option is C

Step 1: Understanding the reaction.
The reaction involves the hydrogenation of benzyl chloride using palladium on barium sulfate (Pd/BaSO\(_4\)) to form benzaldehyde. In this reaction, the -CH\(_2\)Cl group is converted into -CHO, leading to the formation of benzoyl chloride (C\(_6\)H\(_5\)-COCl).
Step 2: Analyzing the options.
(A) Benzoic acid: This is incorrect. The product is benzoyl chloride, not benzoic acid.
(B) Benzyl chloride: This is incorrect. Benzyl chloride is the starting material, not the product.
(C) Benzoyl chloride: This is correct. The product of this reaction is benzoyl chloride.
(D) Chlorobenzene: This is incorrect. The reaction does not form chlorobenzene.
Step 3: Conclusion.
The correct answer is (C) Benzoyl chloride.