1 M HCl solution have a higher concentration of H⁺ ions than 1 M CH₃COOH solution because HCl is a strong acid than CH₃COOH. Hence the H in HCl is able to dissociate very quickly from its formula unit mass and gets liberated in the form of H⁺ very quickly leading to a rapid increase in the H⁺ concentration but CH₃COOH is a weak acid and the H present in it is not able to dissociate quickly and completely from its formula unit mass in the form of H⁺ ionswhich leads to a slow increase in the H⁺ ion concentration and a low concentration of H⁺ ions in the solution.