The correct statement(s) regarding sugars is (are)
Given: Specific rotations of L-(-)-glucose and L-(+)-fructose are -52.5° and +92.5°, respectively.
(A)On treatment with HNO3, gluconic acid is oxidized to saccharic acid, whereas glucose is not oxidized to saccharic acid
(B)Fructose gives a positive Fehling's test because it isomerises to glucose and another aldohexose in the presence of Fehling's reagent✓ Correct
(C)Invert sugar is an equimolar mixture of D-glucose and D-fructose formed after hydrolysis of the corresponding disaccharide✓ Correct
(D)Specific rotation of invert sugar is −40°
Answer: (B), (C)
Solution
(A) Incorrect: Both gluconic acid and glucose are oxidized to saccharic acid by HNO₃. Glucose is oxidized at both ends (aldehyde and primary alcohol) to give saccharic acid.
(B) Correct: Fructose gives positive Fehling's test because in the basic medium of Fehling's solution, fructose tautomerizes to D-glucose and D-mannose (aldohexoses), which then reduce the Cu²⁺ to Cu⁺.
(C) Correct: Invert sugar is indeed an equimolar mixture of D-glucose and D-fructose formed after acidic hydrolysis of sucrose.
(D) Incorrect: Specific rotation of invert sugar = 2(+52.5°)+(−92.5°)=−20°, not -40°.
Therefore, options (B) and (C) are correct.
JEE Advanced · 2026 · 17 May 2026 · Paper 2 · One or more correct options
