Question

The correct combination of names for isomeric alcohols with molecular formula $C_4{H}_{10}O$ is / are

• A. tert-butanol and 2-methylpropan-2-ol
• B. tert-butanol and 1, 1-dimethylethan-1-ol
• C. n-butanol and butan-1-ol
• D. iso-butyl alcohol and 2-methylpropan-1-ol

Answer 1

Answer: (A), (C), (D)

The correct options are
A tert-butanol and 2-methylpropan-2-ol
C n-butanol and butan-1-ol
D iso-butyl alcohol and 2-methylpropan-1-ol

We need to draw the structure of each isomeric form that is possible and write the IUPAC name.

To get the various isomeric forms, we will use the methods discussed like

- changing the chain length which gives chain isomers
- changing the position of the alkyl group or functional group within the chain which gives position isomers
- changing the functional group itself which would give us functional isomers but in this case, we need only alcohols.

If we do that, we will end up with the following.

Formula	Names
$C{H}_{3}C{H}_{2}C{H}_{2}C{H}_{2}OH$	n-butyl alcohol / n-butanol / butan-1-ol
$C{H}_3-\underset{\underset{C{H}_3}{|}}{CH}-C{H}_2-OH$	Iso-butyl alcohol / 2-methyl propan-1-ol
$C{H}_3-C{H}_2-\underset{\underset{C{H}_3}{|}}{CH}-OH$	Secondary butyl alcohol / butan-2-ol
$C{H}_3-\underset{\underset{C{H}_3}{|}}{\stackrel{\stackrel{C{H}_3}{|}}{C}}-OH$	Tertiary butyl alcohol / tert-butanol / 2-methyl propan-2-ol