Question

Which of the following reagents forms semicarbazone when treated with ketones?

• A. Hydroxyl amine
• B. Hydrazine
• C. Phenyl hydrazine
• D. Semicarbazide

Hint:

Each nitrogen reagent gives its own derivative; semicarbazide gives semicarbazone.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Ketones react with ammonia derivatives (\(\text{NH}_{2}-\text{Z}\)) to give C=N-Z compounds with loss of water.

Step 2: Match Reagent and Product
Hydroxylamine gives an oxime.
Hydrazine gives a hydrazone.
Phenylhydrazine gives a phenylhydrazone.
Semicarbazide gives a semicarbazone.

Step 3: Compare the options
The reagent is semicarbazide, option (D).

Final Answer:
Semicarbazide forms semicarbazones with ketones. \[ \boxed{\text{(D) }\text{Semicarbazide}} \]