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CBSE Class 12 · 2004 · All India Compartment · Aldehydes Ketones and Carboxylic AcidsShort Answer

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Give chemical tests to distinguish between the following pairs of compounds:
i) phenol and benzoic acid
ii) benzaldehyde and acetophenone

Solution

(i) Benzoic acid + NaHCO → CO effervescence; phenol gives none (phenol + neutral FeCl → violet).
(ii) Benzaldehyde reduces Tollens' reagent to a silver mirror; acetophenone does not — conversely, acetophenone (CHCO–) gives yellow CHI in the iodoform test, benzaldehyde does not.

CBSE Class 12 Board · 2004 · All India Compartment · Subjective

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