Answer:
Step-by-step explanation:
When a strong acid (HCl) is added to a solution, the buffer system resists a significant change in pH. A buffer system is a combination of a weak acid and its conjugate base (or a weak base and its conjugate acid) that helps maintain the pH of a solution within a relatively narrow range.
In the case of a buffer system containing a weak acid (HA) and its conjugate base (A^-), when a strong acid (HCl) is added, the following chemical reaction occurs:
HA + HCl → A^- + H2O
Here, the strong acid (HCl) reacts with the weak acid (HA) of the buffer system to form its conjugate base (A^-) and water (H2O). The addition of the strong acid is effectively neutralized by the buffer system because the newly formed conjugate base (A^-) can act as a proton acceptor, combining with any additional H+ ions released by the strong acid.
In other words, the weak acid in the buffer system can release protons (H+) to counteract the increase in H+ ions from the strong acid, while the conjugate base can accept protons to mitigate a decrease in H+ ions.
This process of proton transfer helps to stabilize the pH of the solution, maintaining it within a relatively constant range. The buffer system effectively resists large changes in pH, making it essential for maintaining the pH of biological systems, chemical reactions, and various industrial processes.