NEET 2026 Chemistry Oxidation Reactions MCQ Question

Topic: Aldehydes & Ketones → Oxidation Reactions Difficulty: 🟡 Medium

✅ Ans: D

P = Acetophenone $(C_6H_5COCH_3)$

• Gives 2,4-DNP precipitate → confirms carbonyl group.
• Does not reduce Fehling’s reagent → P is a ketone, not an aldehyde.
• On drastic oxidation, the side chain is oxidised to –COOH:

$$C_6H_5COCH_3 \xrightarrow[\text{drastic oxidation}]{H_2CrO_4} C_6H_5COOH$$

So,

$$\boxed{P=\text{Acetophenone},\quad Q=\text{Benzoic acid}}$$

❌ Why others are wrong?

• A ❌ → oxidation product shown is incorrect.
• B ❌ → P is an aldehyde, which should reduce Fehling’s reagent.
• C ❌ → P is an aldehyde, so it should give a positive Fehling’s test.

📌 NCERT: Ketones generally do not reduce Fehling’s solution, whereas aldehydes do.

🧠 NEET Trick: 2,4-DNP + Fehling’s negative → Ketone → aromatic methyl ketone on strong oxidation → benzoic acid.