JEE Advanced2026ChemistryBiomoleculesActual
The correct statement(s) regarding sugars is(are) Given: Specific rotations of L-( - )-glucose and L-( + )-fructose are -52.5^ and +92.5^ , respectively.
Options
- AOn treatment with HNO ₃ , gluconic acid is oxidized to saccharic acid, whereas glucose is not oxidized to sacc
- BFructose gives a positive Fehling's test because it isomerises to glucose and another aldohexose in the presen
- CInvert sugar is an equimolar mixture of D-glucose and D-fructose formed after hydrolysis of the corresponding
- DSpecific rotation of invert sugar is -40^ .
Correct answer
B. Fructose gives a positive Fehling's test because it isomerises to glucose and another aldohexose in the presen
Step-by-step solution
Statement (A) is incorrect: Nitric acid ( HNO ₃ ) is a strong oxidizing agent that oxidizes both glucose and gluconic acid to saccharic acid. Statement (B) is correct: Fehling's reagent provides an alkaline medium. Under these conditions, fructose (a ketose) undergoes the Lobry de Bruyn-van Ekenstein rearrangement to form an equilibrium mixture of fructose, glucose, and mannose. Glucose and mannose are aldohexoses that readily reduce Fehling's solution, giving a positive test. Statement (C) is correct: Hydrolysis o