Question

Why chloroacetic acid is stronger than acetic acid?

Answer 1

Chloroacetic acid is stronger, because it contains (more electronegative) chlorine atoms in the place of (less electronegative) hydrogen atoms.

Answer 2

Explanation:

An acid that will readily dissociate to give hydrogen ions or protons will be considered as a strong acid.

Chloroacetic acid $(ClCH_{2}COOH)$ contains an electronegative chlorine atom which is also electron withdrawing in nature.

Therefore, it will attract the negative charge towards itself through the inductive effect. As a result, negative charge density on oxygen atom will get reduced and cholroacetic acid will readily give hydrogen ion.

Hence, conjugate base of chloroacetic acid will get stabilized.

Whereas acetic acid $(CH_{3}COOH)$ has an electron donating group that is the methyl group. Hence, eletron density will increase on oxygen atom and it will not lose hydrogen ions.

Therefore, acetic acid will be a weak acid as compared to chloroacetic acid.