AIIMS2017Chemistry-Alcohols, Phenols and Ethers

AIIMS 2017 Chemistry Reactions of Alcohols MCQ Question

Type: MCQ-conceptual-Medium-Class 12

A primary alcohol with a vapour density of 29 contained C = 62.1%, H = 10.3% and reacted with bromine to give a derivative which contains C = 16.5%, H = 2.7% and Ba = 73.4%. The structural formula of the compound is

A

CH₃CH₂CH₂OH

B

CH₃CH = CHOH

C

CH₂ = CH - CH₂OH

Correct Answer

Option C

Detailed Explanation

Option C, CH₂=CH-CH₂OH, is correct because it is a primary alcohol that fits the given composition of carbon (C), hydrogen (H), and the derived bromine compound. The vapour density of 29 indicates a molecular weight of approximately 58 g/mol, consistent with this structure, which contains three carbon atoms and one hydroxyl (−OH) group.

In contrast, option A (CH₃CH₂CH₂OH) has a higher molecular weight and does not match the vapour density. Option B (CH₃CH=CHOH) is an unsaturated alcohol that would not yield the bromine derivative with the specified composition. Option D (Cyclopropanol) is a cyclic alcohol that does not fit the linear formula required for the vapour density and elemental composition provided.

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