JEE Challenger
More from Alcohols, Phenols and Ethers
ChemMedAdv 2014 • Paper 1

Correct Names for Isomeric Alcohols of Formula C4H10O

Identify the correct combination(s) of names corresponding to isomeric alcohols having the chemical formula C4H10O\mathrm{C_4H_{10}O}:

Options

A

tert-butanol and 2-methylpropan-2-ol

Correct
B

tert-butanol and 1, 1-dimethylethan-1-ol

C

n-butanol and butan-1-ol

Correct
D

isobutyl alcohol and 2-methylpropan-1-ol

Correct

Topics & Concepts

Alcohols, Phenols and EthersAlcohols and EthersIsomerismIUPAC Nomenclature

Step-by-Step Solution

To determine the correct combinations of names for the isomeric alcohols of molecular formula C4H10O\mathrm{C_4H_{10}O}, we first identify all four structural isomers of alcohols with this formula along with their correct common and IUPAC names:

  1. Straight-chain primary alcohol: CH3−CH2−CH2−CH2−OH\mathrm{CH_3-CH_2-CH_2-CH_2-OH}

    • Common Name: nn-butanol (or nn-butyl alcohol)
    • IUPAC Name: Butan-1-ol
    • Evaluation of Option (C): "nn-butanol and butan-1-ol" is a correct pair of names for this isomer. Hence, option (C) is correct.

  2. Branched tertiary alcohol: (CH3)3C−OH\mathrm{(CH_3)_3C-OH}

    • Common Name: tert-butanol (or tert-butyl alcohol)
    • IUPAC Name: 2-Methylpropan-2-ol
    • Evaluation of Option (A): "tert-butanol and 2-methylpropan-2-ol" is a correct pair of names for this isomer. Hence, option (A) is correct.
    • Evaluation of Option (B): "1,1-dimethylethan-1-ol" is an incorrect IUPAC name because the longest carbon chain contains 3 carbon atoms (propane derivate), making the correct IUPAC name 2-methylpropan-2-ol. Hence, option (B) is incorrect.

  3. Branched primary alcohol: (CH3)2CH−CH2−OH\mathrm{(CH_3)_2CH-CH_2-OH}

    • Common Name: Isobutyl alcohol
    • IUPAC Name: 2-Methylpropan-1-ol
    • Evaluation of Option (D): "isobutyl alcohol and 2-methylpropan-1-ol" is a correct pair of names for this isomer. Hence, option (D) is correct.

  4. Straight-chain secondary alcohol: CH3−CH2−CH(OH)−CH3\mathrm{CH_3-CH_2-CH(OH)-CH_3}

    • Common Name: sec-butanol
    • IUPAC Name: Butan-2-ol

Thus, the correct options are A, C, and D.

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