Module #8: More On Equilibrium

Question 1

Buffer Solution

Answer 1

A solution made up of a weak acid and its conjugate base. These solutions are resistant to change in pH.

Question 2

Buffer capacity

Answer 2

The amount of acid or base that can be added to a buffer solution before its pH changes significantly

Question 3

What is the equation for the change in pH of a Buffer Solution?

Answer 3

pH = pKa + log([A-]/[HA])

It is the Henderson-Hasselbalch equation

Question 4

What is pKa in the Henderson-Hasselbalch equation?

Answer 4

pKa = -log (Ka)

It is the negative log of the weak acid’s Ka in a Buffer Solution

Question 5

What do [A-] and [HA] stand for in the Henderson-Hasselbalch equation?

Answer 5

[HA] stands for the concentration of the weak acid in a Buffer Solution, and [A-] stands for the concentration of the Conjugate base of the weak acid in a Buffer Solution.