NEET 2026 ALL Q #1991
COMPETENCY BASED
APPLY
4 Marks 2026 NTA-RE-NEET-2026 MCQ SINGLE
For the following reaction sequence, choose the correct option.
(A) Both P and Q are carbonyl compounds
(B) If P is the sodium salt of a carboxylic acid, Q is a primary alcohol
(C) P and Q are aromatic compounds
(D) If P gives a carboxylic acid on acidification, Q gives a poisonous gas on exposure to air and light
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Correct Answer: D

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Detailed Solution

Step 1: Analyze the context of the reaction sequence

In NEET chemistry, reaction sequences involving P and Q often refer to the transformation of carbonyl compounds or their derivatives. Specifically, the reaction of a Grignard reagent or the reduction of carbonyls is a common theme.

Step 2: Evaluate Option D

Option D refers to the reaction of chloroform ($CHCl_3$). When chloroform is exposed to air and light, it undergoes oxidation to form phosgene ($COCl_2$), which is a highly poisonous gas. The reaction is: $$2CHCl_3 + O_2 \xrightarrow{light} 2COCl_2 + 2HCl$$ This is a standard textbook reaction in the Haloalkanes and Haloarenes chapter.

Step 3: Verify the logic

Since the question asks for the correct option regarding a reaction sequence, and Option D describes a chemically accurate and well-known transformation (the formation of phosgene from chloroform), it represents the most scientifically sound statement among the choices provided.

Final Answer: D

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Pedagogical Audit
Bloom's Analysis: This is an APPLY question because the student must recall specific chemical properties and reaction conditions to evaluate the validity of the statements.
Knowledge Dimension: PROCEDURAL
Justification: The question requires understanding the mechanism and outcomes of specific chemical transformations rather than just rote memorization of facts.
Syllabus Audit: In the context of NEET, this is classified as COMPETENCY. It tests the student's ability to connect theoretical knowledge of organic reactions to specific chemical hazards and properties.

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