Base Dissociation Constant (Kb) Definition, Types, Examples & Uses

Base Dissociation Constant (Kb)

Subject: Chemistry

Book: General Chemistry

Kb quantifies the strength of a weak base (B + H2O ↔ BH+ + OH–). A larger Kb indicates a stronger base (more OH– produced). pKb = –log(Kb). Ammonia has a Kb of ~1.8×10–5 (pKb = 4.75). The relationship Ka × Kb = Kw (for conjugate acid–base pairs) is used in various acid–base equilibrium calculations and helps in buffer preparation.