Q9 / 150 · MHT CET 2026 (19 April Shift 1) · Chemistry
What is the number of $sp^3$ hybrid carbon atoms in $\text{HO}(\text{CH}_2)_2\text{CH}(\text{CH}_3)_2$?
- A$2$
- B$3$
- C$4$
- Correct answerD$5$
Solution
The given molecule is 3-methylbutan-1-ol, with the expanded structural formula $\text{HO}-\text{CH}_2-\text{CH}_2-\text{CH}(\text{CH}_3)-\text{CH}_3$.
In this structure, every carbon atom is bonded to four other atoms (either carbon, hydrogen, or oxygen) entirely through single ($\sigma$) bonds.
Since there are no $\pi$ bonds present, all the carbon atoms are $sp^3$ hybridized.
Counting the carbon atoms:
Two $-\text{CH}_2-$ groups $\rightarrow 2$ carbon atoms
One $-\text{CH}-$ group $\rightarrow 1$ carbon atom
Two $-\text{CH}_3$ groups $\rightarrow 2$ carbon atoms
Total number of $sp^3$ hybridized carbon atoms $= 2 + 1 + 2 = 5$.
In this structure, every carbon atom is bonded to four other atoms (either carbon, hydrogen, or oxygen) entirely through single ($\sigma$) bonds.
Since there are no $\pi$ bonds present, all the carbon atoms are $sp^3$ hybridized.
Counting the carbon atoms:
Two $-\text{CH}_2-$ groups $\rightarrow 2$ carbon atoms
One $-\text{CH}-$ group $\rightarrow 1$ carbon atom
Two $-\text{CH}_3$ groups $\rightarrow 2$ carbon atoms
Total number of $sp^3$ hybridized carbon atoms $= 2 + 1 + 2 = 5$.
Hence, the correct answer is option: 'D'.