Q38 / 150 · MHT CET 2026 (11 April Shift 2) · Chemistry
The number of primary isomeric alcohols of the molecular formula $\text{C}_4\text{H}_{10}\text{O}$ is
- A$1$
- Correct answerB$2$
- C$3$
- D$4$
Solution
The molecular formula $\text{C}_4\text{H}_{10}\text{O}$ represents saturated acyclic alcohols and ethers.
Primary alcohols have the general formula $\text{R}-\text{CH}_2-\text{OH}$. For $\text{C}_4\text{H}_{10}\text{O}$, the alkyl group $\text{R}$ must be a propyl group ($\text{C}_3\text{H}_7$).
There are two isomeric propyl groups:
1. n-propyl group: $-\text{CH}_2\text{CH}_2\text{CH}_3$
2. isopropyl group: $-\text{CH}(\text{CH}_3)_2$
Attaching these to the $-\text{CH}_2\text{OH}$ group gives two primary alcohols:
1. $\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{OH}$ (Butan-1-ol)
2. $\text{CH}_3\text{CH}(\text{CH}_3)\text{CH}_2\text{OH}$ (2-Methylpropan-1-ol)
Thus, there are 2 primary isomeric alcohols.
Answer: $2$
Primary alcohols have the general formula $\text{R}-\text{CH}_2-\text{OH}$. For $\text{C}_4\text{H}_{10}\text{O}$, the alkyl group $\text{R}$ must be a propyl group ($\text{C}_3\text{H}_7$).
There are two isomeric propyl groups:
1. n-propyl group: $-\text{CH}_2\text{CH}_2\text{CH}_3$
2. isopropyl group: $-\text{CH}(\text{CH}_3)_2$
Attaching these to the $-\text{CH}_2\text{OH}$ group gives two primary alcohols:
1. $\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{OH}$ (Butan-1-ol)
2. $\text{CH}_3\text{CH}(\text{CH}_3)\text{CH}_2\text{OH}$ (2-Methylpropan-1-ol)
Thus, there are 2 primary isomeric alcohols.
Answer: $2$
Hence, the correct answer is option: 'B'.