Chloroacetic acid is a stronger acid than acetic acid. This can be explained using

Step-by-step solution

-Cl is an electron withdrawing (ie, -I showing) group. It withdraws electrons when attached to the carboxylic acid and decreases the electron density on the oxygen atom. This will facilitate the release of H ⁺ by making O - H bond more polar and thus - Cl increases the acidity of acetic acid when attached at, position because of -I effect.