Question

Acidity of formic acid is more than acetic acid....How?

Answer 1

Hey mate here is your answer...
Acetic acid is stabilised by the presence of the methyl group. Formic acid, in contrast, is not stable, and can decompose to water and carbon monoxide.

Formic acid is more acidic because it lacks a methyl group. The methyl group in acetic acid is slightly electron donating. This stabilises the O-H bond in the acid group, making acetic acid less acidic than would be predicted. In formic acid, this stabilising effect does not occur, and the acidic proton is lost more easily.
So, Acidity of formic acid is more than acetic acid.

Answer 2

Answer:

Out of acetic acid and formic acid, formic acid is considered stronger because the CH3 in acetic acid is electron donating. The CH3 actually contributes electron density towards the O-H bond, making it harder to remove the H, and making acetic acid a weaker acid than formic acid.