Ques. 1NEET (UG) 2026
Compound P(C8H8O) gives a red orange precipitate with 2,4-DNP reagent and it does not reduce Fehling's reagent. On drastic oxidation with chromic acid, P gives an aromatic product Q that produces effervescence on treating with aq. NaHCO3. Compounds P and Q, respectively, are :
- P = [figure] ; Q = [figure]
- P = [figure] ; Q = [figure]
- P = [figure] ; Q = [figure]
- P = [figure] ; Q = [figure]
Answer
(2) P = [figure] ; Q = [figure]
Solution
2,4-DNP test positive (red orange ppt.) ⇒ P is a carbonyl compound.
Does not reduce Fehling's reagent ⇒ P is not an aldehyde ⇒ P is a ketone.
C8H8O aromatic ketone ⇒ P = acetophenone, C6H5COCH3
As per NCERT, on vigorous oxidation the side chain of an aromatic ketone is oxidised to –COOH:
[figure]
Q = benzoic acid; C6H5COOH + NaHCO3 C6H5COONa + H2O + CO2 (effervescence)
Answer: (2)