Question

Identify the name of second higher homologue of formic acid?

• A. Methanoic acid
• B. Ethanoic acid
• C. Propanoic acid
• D. Butanoic acidaa

Hint:

Homologues differ by one CH2 unit, so count up from HCOOH twice.

Answer 1

The Correct Option is C

Step 1: Count carbon atoms:
Formic acid has $1$ carbon. The first higher homologue has $2$ carbons, the second has $3$ carbons.

Step 2: Name:
A carboxylic acid with three carbons is propanoic acid, $\text{C}_2\text{H}_5\text{COOH}$.
Butanoic acid has four carbons, so it is the third higher homologue, not the second.

Final Answer:
The answer is propanoic acid, option (C). \[ \boxed{\text{Propanoic acid}} \]