Answer:
a. A buffer solution reacts with basic solutions.
c. A buffer solution reacts with acidic solutions.
e. A buffer solution resists small changes in pH
Explanation:
1. Buffer questions
a, c, and e are TRUE. A buffer resists a change in the pH when small amounts of a strong acid or base are added to it.
b is wrong. A buffer can have a pH of 7, but it can also have many other pH values.
d is wrong. Most buffers are colourless, and they resist a change in pH.
2. Titration curves
The solution is the best buffer at the mid-point of the titration curve.
In the figure below, the equivalence point is at 13 mL, so the mid-point is at 6.5 mL.
The solution is buffered at pH 3.2.
However, the solution is a buffer at any point in the range pH = 3.2 ± 1.
That would be in the range of 1 mL to 12 mL.
The buffering ability becomes worse the further you are from the mid-point of the titration.
