What does Fehling's solution test detect?
AAcid
BAliphatic aldehydes (gives red Cu₂O precipitate)
CAll ketones
DPhenols
Answer & Solution
Correct answer: B. Aliphatic aldehydes (gives red Cu₂O precipitate)
Fehling's reagent (Cu²⁺ in alkaline tartrate): aliphatic aldehydes reduce Cu²⁺ → red Cu₂O. Aromatic aldehydes (e.g., PhCHO) and ketones give NEGATIVE Fehling test. Tollens distinguishes aliphatic vs aromatic better.
Related questions
Integration: ∫ tan(x) dx =If f(x) = x³ - 3x² + 2, find x where local maximum occurs:For y = cos x, y'' + y =Find eigenvalues of [[3, 1], [1, 3]]:In a triangle ABC, if a = 2, b = 3, C = 60°, find c (using cosine rule):sin(75°) =Roots of equation x² - 5x + 6 = 0:Distance from point (1, 2, 3) to plane x + y + z - 6 = 0: