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Fehling's test positive for:
AKetone
BBoth
CAromatic aldehyde
DALIPHATIC aldehyde (gives red Cu₂O precipitate)
Answer & Solution
Correct answer: D. ALIPHATIC aldehyde (gives red Cu₂O precipitate)
Fehling's reagent: Cu²⁺ in alkaline tartrate. Aliphatic aldehydes reduce Cu²⁺ to red Cu₂O. Aromatic aldehydes (like benzaldehyde) do NOT give Fehling's test (more stable due to resonance). So both Tollens' AND Fehling's together distinguish aliphatic vs aromatic aldehydes.
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