Adding a strong acid to a chemical equilibrium system containing a weak acid will affect the ionization of the weak acid by shifting the equilibrium position and decreasing the extent of ionization of the weak acid. This can be explained using Le Chatelier's principle, which states that if a stress is applied to a system at equilibrium, the system will adjust to counteract the stress and re-establish equilibrium.Let's consider an example with acetic acid CH3COOH , a weak acid, and hydrochloric acid HCl , a strong acid. The ionization of acetic acid in water can be represented by the following equilibrium reaction:CH3COOH aq + H2O l CH3COO- aq + H3O+ aq When a strong acid like HCl is added to the system, it will dissociate completely in water, releasing a large amount of H3O+ ions:HCl aq + H2O l H3O+ aq + Cl- aq The increase in H3O+ concentration will cause a stress on the equilibrium system of the weak acid. According to Le Chatelier's principle, the system will try to counteract this stress by shifting the equilibrium position to the left, favoring the formation of reactants CH3COOH and consuming some of the H3O+ ions. This shift will result in a decrease in the ionization of the weak acid acetic acid , as less CH3COO- and H3O+ ions will be formed.In summary, adding a strong acid to a chemical equilibrium system containing a weak acid will decrease the ionization of the weak acid by shifting the equilibrium position towards the reactants, as the system tries to counteract the increase in H3O+ ions according to Le Chatelier's principle.