Formic acid vs acetic acid strength — UPSC Prelims PYQ 1998

Consider the following statements

1. Assertion (A): Formic acid is a stronger acid than acetic acid.
2. Reason (R): Formic acid is an organic acid.

Select the correct answer using the code given below:

1. Both A and R are true, and R is the correct explanation of A
2. Both A and R are true, but R is NOT the correct explanation of A
3. A is true, but R is false
4. A is false, but R is true

Explanation

Option (b) is correct

• Formic acid is a stronger acid than Acetic acid because the methyl group (CH 3 ​ ) in acetic acid exerts an electron-releasing (+I) effect, which decreases the tendency to release H + ions. Formic acid lacks such an electron-donating group, making it comparatively stronger. The Reason is true because formic acid is indeed an organic acid, but this does not explain why it is stronger than acetic acid.

Answer: (a) Both A and R are true, and R is the correct explanation of A