Question

A buffer solution is 0.100 M in both HC7H5O2 and LiC7H5O2 and has a pH of 4.19. Which of the following pH values would you expect from the addition of a small amount of a dilute solution of a strong acid?

Answer 1

When a small amount of a strong acid is added to a buffer solution, the pH of the buffer solution is expected to decrease. This is because the added acid will react with the base component of the buffer (in this case, LiC7H5O2) to form the corresponding salt and water, thereby decreasing the concentration of the base and increasing the concentration of the acid.

Since the initial pH of the buffer solution is 4.19, which is less than 7, it indicates that the solution is acidic. Therefore, the addition of a strong acid would further decrease the pH. Among the given pH values, we would expect a decrease in pH to a value less than 4.19.

Therefore, the expected pH value would be either 3.7 or 3.9.