NEET Chemistry Question (2026) — Solution

Step-by-step solution

The first step is the Friedel-Crafts acylation of benzene with acetyl chloride ( CH _3 COCl ) and anhydrous AlCl _3, which produces acetophenone ( C _6 H _5 COCH _3). The second step is the haloform reaction. Acetophenone has a methyl ketone group and reacts with sodium hypochlorite ( NaOCl ) to form sodium benzoate ( C _6 H _5 COONa ) and chloroform ( CHCl _3). Thus, the products P and Q are sodium benzoate and chloroform. Sodium benzoate ( P ) on acidification yields benzoic acid ( C _6 H _5 COOH ). Chloroform ( Q ) on exposure to air and light oxidizes to form phosgene ( COCl _2), a highly poisonous gas, according to the reaction: 2 CHCl _3 + O _2 light 2 COCl _2 + 2 HCl Therefore, if P gives a carboxylic acid on acidification, Q gives a poisonous gas on exposure to air and light. Answer: If P gives a carboxylic acid on acidification, Q gives a poisonous gas on exposure to air and light.