A small amount of acid is added to a buffer solution. The pH of the solution will
A. increase.
B. decrease.
C. stay about the same.****
D. become neutral.
The correct answer is C. stay about the same.
A buffer solution is a solution that resists changes in pH when small amounts of acid or base are added. It consists of a weak acid and its conjugate base, or a weak base and its conjugate acid. The weak acid or base can react with the added acid or base to minimize changes in pH.
When a small amount of acid is added to a buffer solution, the weak acid in the buffer will react with the added acid to neutralize it. This reaction will produce its conjugate base, which can then act as a base and accept any additional acid that is added. As a result, the pH of the buffer solution will remain relatively stable.
It's important to note that the pH will not stay exactly the same, but it will change only slightly compared to what would happen if the buffer were not present. The buffer's ability to resist changes in pH is what allows it to maintain its effectiveness even in the presence of additional acid or base.