why formic acid is more acidic than 2-chloro ethnoic acid or any other -i containing group?

Question

this is exception;but reason what i think that in -i containing group there is partial shifting of electron cloud which create partial +ive on c but this cannot be happen in formic acid.

Answer 1

u know when O will loose H -ve charge will come on it and in formic acid this -ve charge will get stablised by resonance

whereas in other one as cl is -i grp the effective resonance will not be effective as in formic due to delta +ve charge on carbon to which CL is attached

that is why more the resonance more stablise dwill b the structure hence more acidic will b formic acid

Answer 2

the reason might be the absence of methyl or i.e. alpha carbon in formic acid. as in ethanoic acid, the methyl group (due to +I effect) shifts electrons towards the carbonyl carbon ,, thus stabilizing the positive charge on the carbonyl carbon
in 2-chloro ethanoic acid, even though an electron withdrawing group (-Cl) is present , i think the electron releasing effect of the methyl group is more.
and as formic acid does not have an electron releasing group, it is more acidic than 2chloro ethanoic acid