Q41 / 150 · MHT CET 2026 (17 April Shift 2) · Chemistry
What is the name of second lower homologue of $\text{CH}_3(\text{CH}_2)_2\text{COOH}$ ?
- AMethanoic acid
- Correct answerBEthanoic acid
- CPropanoic acid
- DPentanoic acid
Solution
The given compound is $\text{CH}_3(\text{CH}_2)_2\text{COOH}$, which contains 4 carbon atoms and is named butanoic acid.
Homologues in a series differ by a successive $-\text{CH}_2-$ unit.
The first lower homologue has one less $-\text{CH}_2-$ unit, which is $\text{CH}_3\text{CH}_2\text{COOH}$ (propanoic acid).
The second lower homologue has two less $-\text{CH}_2-$ units, which is $\text{CH}_3\text{COOH}$ (ethanoic acid).
Answer: Ethanoic acid
Homologues in a series differ by a successive $-\text{CH}_2-$ unit.
The first lower homologue has one less $-\text{CH}_2-$ unit, which is $\text{CH}_3\text{CH}_2\text{COOH}$ (propanoic acid).
The second lower homologue has two less $-\text{CH}_2-$ units, which is $\text{CH}_3\text{COOH}$ (ethanoic acid).
Answer: Ethanoic acid
Hence, the correct answer is option: 'B'.