## Chemistry: Molecular Approach (4th Edition)

The acid ionization constant is an equilibrium constant for the ionization reaction of a weak acid. It is used to quantify the strength of a weak acid, which means: the higher the $K_a$, the stronger the acid. It is defined mathematically with this equation: Ionization: $$HA(aq) + H_2O(l) \leftrightharpoons A^-(aq)+ H_3O^+(aq)$$ $$K_a = \frac{[A^-][H_3O^+]}{[HA]}$$ It is a very important concept for the study of acid equilibrium, since it is useful to calculate the amount of $H_3O^+$ produced at equilibrium with the initial concentration of the acid or vice versa.
The acid ionization constant is an equilibrium constant for the ionization reaction of a weak acid. It is used to quantify the strength of a weak acid, which means: the higher the $K_a$, the stronger the acid. It is defined mathematically with this equation: Ionization: $$HA(aq) + H_2O(l) \leftrightharpoons A^-(aq)+ H_3O^+(aq)$$ $$K_a = \frac{[A^-][H_3O^+]}{[HA]}$$ It is a very important concept for the study of acid equilibrium, since it is useful to calculate the amount of $H_3O^+$ produced at equilibrium with the initial concentration of the acid or vice versa.