Question

Select all of the statements that are true about a buffer solution. Select one or more: a. A buffer solution reacts with basic solutions. b. A buffer solution has a pH of 7. c. A buffer solution reacts with acidic solutions. d. A buffer solution always changes color when the pH changes. e. A buffer solution resists small changes in pH. Question 13 Not yet answered Marked out of 1.00 Not flaggedFlag question Question text At what point on the titration curve for a weak acid is the solution a buffer

Answer 1

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.