Question

Fehling’s solution

• A. contains a copper complex of tartaric acid
• B. forms a brick-red precipitate with glucose
• C. forms a white precipitate with aldehydes
• D. is used as a test reagent for reducing sugars

Hint:

Fehling’s test: aldehyde or reducing sugar → brick-red Cu$_2$O precipitate.

Answer 1

The Correct Option is A, B, D

Step 1: Recall composition of Fehling’s solution.
Fehling’s reagent contains Cu$^{2+}$ ions complexed with tartrate in an alkaline medium. It is used to detect reducing sugars.
Step 2: Identify reactions.
Aldehydes reduce Cu$^{2+}$ → Cu$_2$O, giving a brick-red precipitate. Thus, option (B) is true, and (D) is also true. (A) is also correct regarding chemical composition.
Step 3: Determine incorrect statement.
(C) is incorrect because aldehydes do NOT form a white precipitate; they form a brick-red precipitate of Cu$_2$O.
Step 4: Conclusion.
Thus, the incorrect statement (and the expected answer) is (C).