Question

Which reagent is used to distinguish between ethanal and propanone?

• A. Tollen's reagent
• B. Sodium hydroxide
• C. Ethanol
• D. Acetic acid

Hint:

Tollen's test: \[ \text{Aldehyde} \rightarrow \text{Silver Mirror} \] \[ \text{Ketone} \rightarrow \text{No Reaction} \]

Answer 1

The Correct Option is A

Concept: Tollen's reagent distinguishes aldehydes from ketones. Composition: \[ [Ag(NH_3)_2]^+ \] Aldehydes reduce silver ions to metallic silver.

Step 1: Analyze ethanal.
Ethanal is an aldehyde. \[ CH_3CHO \] It gives silver mirror test.

Step 2: Analyze propanone.
Propanone is a ketone. \[ CH_3COCH_3 \] It does not reduce Tollen's reagent.

Step 3: Observation.
Ethanal: \[ \text{Silver Mirror} \] Propanone: \[ \text{No reaction} \] Thus distinction is possible. \[ \boxed{\text{Tollen's reagent}} \]