Step 1: Understanding the Concept:
Distinguishing between organic compounds involves using specific chemical tests that react with one functional group but not the other, or produce a unique visible change (color, smell, precipitate). Step 2: Detailed Explanation: A. Diethyl amine + Ethyl amine:
Diethyl amine is a secondary (\(2^{\circ}\)) amine, and Ethyl amine is a primary (\(1^{\circ}\)) amine. Primary amines react with \(CHCl_3\) and \(KOH\) to give a foul-smelling isocyanide (Carbylamine test). Secondary amines do not.
Match: A \(\rightarrow\) II. B. Acetaldehyde + Acetone:
Acetaldehyde is an aldehyde, and Acetone is a ketone. Aldehydes reduce Tollens' reagent (Ammoniacal silver nitrate) to form a silver mirror. Ketones do not.
Match: B \(\rightarrow\) IV. C. Ethanol + Phenol:
Phenols react with neutral \(FeCl_3\) to produce a characteristic violet/purple color due to complex formation. Simple alcohols like ethanol do not show this reaction.
Match: C \(\rightarrow\) III. D. Benzoic acid + Cinnamic acid:
Cinnamic acid (\(Ph-CH=CH-COOH\)) is unsaturated, whereas benzoic acid is saturated. Cinnamic acid will decolorize Bromine water due to addition across the double bond.
Match: D \(\rightarrow\) I.
Final Match: A-II, B-IV, C-III, D-I. Step 3: Final Answer:
The correct match is A-II, B-IV, C-III, D-I.
