STATEMENT-1 : Glucose gives a reddish-brown precipitate with Fehling's solution.
because
STATEMENT-2 : Reaction of glucose with Fehling's solution gives CuO and gluconic acid.
because
STATEMENT-2 : Reaction of glucose with Fehling's solution gives CuO and gluconic acid.
- (A)Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
- (B)Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
- (C)Statement-1 is True, Statement-2 is False✓ Correct
- (D)Statement-1 is False, Statement-2 is True
Answer: (C)
Solution
Statement-1 is true: glucose, being a reducing sugar with a free aldehyde group, gives a reddish-brown precipitate with Fehling's solution. Statement-2 is false: the reaction produces Cu₂O (cuprous oxide, red-brown precipitate), not CuO (cupric oxide, black). The glucose is oxidized to gluconic acid while Cu²⁺ in Fehling's solution is reduced to Cu⁺, which precipitates as Cu₂O.
JEE Advanced · 2007 · 08 Apr 2007 · Paper 2 · Single correct option