Weak Acid + Weak Base Salt

$$K_h = \frac{K_w}{K_a \cdot K_b} \qquad h = \sqrt{K_h} \qquad \text{pH} = 7 + 0.5 \cdot (\text{p}K_a - \text{p}K_b)$$

Concept: Determines hydrolysis behavior when both ions react with water; notice the degree of hydrolysis is entirely independent of salt concentration.

Notation:

• $$K_h$$ = Hydrolysis constant;
• $$h$$ = Degree of hydrolysis;
• $$K_w$$ = Ionic product of water;
• $$K_a$$ = Acid dissociation constant;
• $$K_b$$ = Base dissociation constant.