Henderson-Hasselbach

Question 1

What is the Henderson-Hasselbalch equation used for?

Answer 1

is an equation used to relate the pH (acidity or basicity) of a solution to the pKa (acid dissociation constant) of a weak acid or weak base in that solution.

Question 2

What is the equation?

Answer 2

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

Question 3

What does the pH stand for?

Answer 3

the negative logarithm of the hydrogen ion concentration in a solution, which indicates the acidity or basicity of the solution.

Question 4

What is the pKa?

Answer 4

is the negative logarithm of the acid dissociation constant of the weak acid (HA), which is a measure of the extent to which the weak acid dissociates into its conjugate base (A-) and hydrogen ions (H+).

Question 5

What is (A-)?

Answer 5

is the concentration of the conjugate base in the solution.

Question 6

What is (HA)?

Answer 6

is the concentration of the weak acid in the solution.

Question 7

What does the Henderson-Hasselbalch equation show?

Answer 7

that the pH of a solution containing a weak acid and its conjugate base depends on the ratio of their concentrations, as well as the pKa of the weak acid

Question 8

What happens when the concentration of the conjugate base ([A-]) is equal to the concentration of the weak acid ([HA])?

Answer 8

The pH of the solution is equal to the pKa of the weak acid.
As the concentration of the conjugate base increases relative to the weak acid, the pH of the solution becomes more basic (higher pH), while as the concentration of the conjugate base decreases relative to the weak acid, the pH of the solution becomes more acidic (lower pH).