Question

Be sure to answer all parts. Does the pH increase or decrease with each of the following additions? To what extent? 5 drops of 0.1 M NaOH added to 100 mL of 0.5 M acetate buffer:

a)decreases to a large extent
b)increases to a large extent
c)decreases to a small extent
d)increases to a small extent

Answer 1

Adding 5 drops of 0.1 M NaOH to 100 mL of a 0.5 M acetate buffer will result in a small increase in pH because of the buffer's ability to neutralize added bases like NaOH.

Step-by-step explanation:

When adding 5 drops of 0.1 M NaOH to 100 mL of a 0.5 M acetate buffer, the pH will increase to a small extent. Buffers are designed to resist changes in pH when small amounts of acid or base are added. Since the buffer in this case is relatively concentrated (0.5 M), it can effectively neutralize the added NaOH, thereby preventing any large changes in pH.

The efficacy of a buffer system is particularly evident when compared to adding the same amount of NaOH to distilled water, which would result in a very large change in pH. However, in a buffered solution, the added base is consumed by the buffer's acidic component, in this case, acetic acid, which will form more acetate ions and thereby only slightly increase the pH of the solution.