JEE Main 2026 — Aldehydes and Ketones Question with Solution
JEE Main 2026 (23 January Shift 2)
Question
Which of the following statements are TRUE about Haloform reaction?:
A. Sodium hypochlorite reacts with KI to give KOI.
B. KOI is a reducing agent.
C. -unsaturated methylketone will give iodoform reaction.
D. Isopropyl alcohol will not give iodoform test.
E. Methanoic acid will give positive iodoform test.
Choose the correct answer from the options given below:
A. Sodium hypochlorite reacts with KI to give KOI.
B. KOI is a reducing agent.
C. -unsaturated methylketone will give iodoform reaction.
D. Isopropyl alcohol will not give iodoform test.
E. Methanoic acid will give positive iodoform test.
Choose the correct answer from the options given below:
Choose an option
Show full solutionCorrect option: C
Correct answer
CA & C Only
Step-by-step explanation
In the haloform reaction:
(A) Sodium hypochlorite reacts with KI in acidic medium to generate the active halogenating species, forming KOI (potassium iodite/hypoidite). TRUE.
(B) KOI serves as an oxidizing agent (not reducing) in the reaction, converting methyl ketones to carboxylic acids. FALSE.
(C) -unsaturated methylketones possess the essential methyl ketone group () required for haloform reaction, allowing iodination and subsequent cleavage. TRUE.
(D) Isopropyl alcohol lacks a methyl ketone group, so it cannot undergo the haloform reaction. TRUE.
(E) Formic acid has no methyl ketone functionality, preventing haloform test. FALSE.
Therefore, statements A and C are true.
(A) Sodium hypochlorite reacts with KI in acidic medium to generate the active halogenating species, forming KOI (potassium iodite/hypoidite). TRUE.
(B) KOI serves as an oxidizing agent (not reducing) in the reaction, converting methyl ketones to carboxylic acids. FALSE.
(C) -unsaturated methylketones possess the essential methyl ketone group () required for haloform reaction, allowing iodination and subsequent cleavage. TRUE.
(D) Isopropyl alcohol lacks a methyl ketone group, so it cannot undergo the haloform reaction. TRUE.
(E) Formic acid has no methyl ketone functionality, preventing haloform test. FALSE.
Therefore, statements A and C are true.
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This is a previous-year question from JEE Main 2026, covering the Aldehydes and Ketones chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.