Please choose the correct option to complete the following statements. (6 marks)

a) If a large amount of base is added to water, the pH of resulting solution would most likely Increase/decrease/remain the same
Explain your choice

b) If a small amount of acid is added to a buffer with pH 6.5, the pH of resulting solution would most likely increase/decrease/remain the same
Explain your choice

c) If a very large amount of strong acid is added to a buffer with pH 6.5, the pH of resulting solution would most likely increase/decrease/remain the same
Explain your choice

I will be happy to critique your thinking on these.

I think it's increase, remain the same and decrease but Im not sure...

Your answers are right. The trick is, can you explain why you're right?

a) If a large amount of base is added to water, the pH of the resulting solution would most likely increase.

Explanation:
To understand why the pH would increase, we need to remember that the pH scale measures the concentration of hydrogen ions (H+) in a solution. Bases are substances that accept protons (H+) and can decrease the concentration of H+ ions in a solution. When a large amount of base is added to water, it would result in the removal of H+ ions from the solution, leading to a decrease in the concentration of H+ ions. As a result, the solution becomes more basic and the pH increases.

b) If a small amount of acid is added to a buffer with pH 6.5, the pH of the resulting solution would most likely remain the same.

Explanation:
A buffer is a solution that can resist changes in pH when small amounts of acids or bases are added. It consists of a weak acid and its conjugate base, which can react with added acid or base to maintain the pH. In this case, since a small amount of acid is added to a buffer with a pH of 6.5, the buffer system will be able to effectively neutralize the added acid, preventing a significant change in pH. Therefore, the pH of the resulting solution would most likely remain the same.

c) If a very large amount of strong acid is added to a buffer with pH 6.5, the pH of the resulting solution would most likely decrease.

Explanation:
A buffer is effective in resisting changes in pH but has its limits. If a very large amount of a strong acid is added to a buffer, it can overwhelm the buffer system's capacity to neutralize the added acid. The excess acid will lead to an increase in the concentration of H+ ions in the solution, causing the pH to decrease. Therefore, in this scenario, the pH of the resulting solution would most likely decrease.