Acid-Base Equilibria

Question 1

What is the acid dissociation constant (Ka)?

Answer 1

Ka is the equilibrium constant for the dissociation of a weak acid in water: HA <-> H+ + A-.

Question 1

How do you calculate Ka from the pH of a weak acid solution?

Answer 1

Determine the concentration of H+ from pH, set up the expression Ka = [H+][A-]/[HA], and sole using the initial concentration of the acid and the degree of ionisation.

Question 2

What is the base dissociation constant (Kb)?

Answer 2

Kb is the equilibrium constant for the dissociation of a weak base in water: B + H2O <-> BH+ + OH-.