2024 Re-NEET Aldehydes, Ketones and Carboxylic AcidsPreparation and reactions of carboxylic acids and amides Medium Question 11 of 91 in Aldehydes, Ketones and Carboxylic Acids

Select the incorrect reaction among the following: (a) CH₃COClH₂O,ΔCH₃COOH; (b) (c) CH₃CH₂OH(i) KMnO₄/OH⁻ (ii) H₃O⁺CH₃COOH; (d) CH₃CH₂CH₂OHCrO₃-H₂SO₄CH₃CH₂COOH

Select the incorrect reaction among the following:
(a) $CH_3COCl\xrightarrow{H_2O,\Delta}CH_3COOH$;
(b)
(c) $CH_3CH_2OH\xrightarrow{(i)\ KMnO_4/OH^-\ (ii)\ H_3O^+}CH_3COOH$;
(d) $CH_3CH_2CH_2OH\xrightarrow{CrO_3-H_2SO_4}CH_3CH_2COOH$
A $CH_3COCl\xrightarrow{H_2O,\Delta}CH_3COOH$
B -
C $CH_3CH_2OH\xrightarrow{(i)\ KMnO_4/OH^-\ (ii)\ H_3O^+}CH_3COOH$
D $CH_3CH_2CH_2OH\xrightarrow{CrO_3-H_2SO_4}CH_3CH_2COOH$

The answer is B.

Solution

$LiAlH_4$ is a reducing agent that reduces an amide ($-CONH_2$) to a primary amine ($-CH_2NH_2$), not to a carboxylic acid. So reaction (b), which shows benzamide converting to benzoic acid on treatment with $LiAlH_4/H_2O$, is incorrect. Reactions (a), (c) and (d) correctly represent hydrolysis of an acid chloride, oxidation of ethanol to acetic acid, and Jones oxidation of a primary alcohol to a carboxylic acid, respectively.

Concept Preparation and reactions of carboxylic acids and amides

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