Final answer:
A buffer solution resists changes in pH when a small amount of acid or base is added. If a buffer is too acidic, or there is excessive rinsing or underbuffering, the pH can change dramatically. An example of a buffer is the bicarbonate system in the human body.
Step-by-step explanation:
A buffer solution is one that resists changes in pH when a small amount of acid or base is added to it. Buffer solutions are typically made by mixing a weak acid and its conjugate base, or a weak base and its conjugate acid. The buffer capacity of a solution refers to its ability to resist changes in pH.
If a stain/buffer is too acidic, it means that the solution has an excess of hydrogen ions. On the other hand, if there is excessive rinsing or underbuffering, the buffer may not be able to resist large changes in pH, and the pH of the solution can change dramatically.
Example: A common buffer used in biological systems is the bicarbonate system in the human body. It helps to prevent large changes in pH in the blood.