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JEE Main · 2023 · 31 Jan 2023 · Shift 2 · Aldehydes Ketones and Carboxylic Acids

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The number of molecules which gives haloform test among the following molecules is ____.
Structure A
A
Structure B
B
Structure C
C
Structure D
D
Structure E
E
Structure F
F

Answer: 3

Solution

A positive haloform test needs a methyl ketone bearing the group, or a secondary alcohol of the type that is first oxidised to such a ketone. Of the six molecules, 2,4-dimethylacetophenone and acetophenone are aryl methyl ketones, and butan-2-ol is a alcohol, so these three respond. The ethyl ketone ester, pentan-3-ol and 2,5,5-trimethylcyclohexane-1,3-dione lack the required unit and do not. The number of molecules giving the haloform test is three.

JEE Main · 2023 · 31 Jan 2023 · Shift 2 · Integer answer

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