In a solution containing a weak acid like acetic acid CH3COOH along with a strong acid like hydrochloric acid HCl , the degree of ionization of the weak acid will be significantly reduced.This is because HCl is a strong acid and will ionize completely in the solution, releasing a large amount of H+ ions. The presence of these H+ ions will suppress the ionization of the weak acid, acetic acid, due to the common ion effect. The common ion effect states that the ionization of a weak electrolyte is suppressed in the presence of a strong electrolyte containing a common ion.In this case, the common ion is the H+ ion. Since the concentration of H+ ions is already high due to the presence of HCl, the equilibrium of the ionization of acetic acid will shift to the left, according to Le Chatelier's principle:CH3COOH CH3COO- + H+As a result, the degree of ionization of acetic acid will be reduced, and the solution will have a lower concentration of acetate ions CH3COO- than if the acetic acid were present alone.