The greater the value of $K_a$, the greater the acid strength. A strong acid almost completely ionizes in solution while a weak acid ionizes minimally in solution. As the strength of an acid increases, the strength of the conjugate base decreases. The greater the value of $K_b$, the greater the base strength. As the strength of a conjugate base increases, the strength of the conjugate acid decreases.
Work Step by Step
As an acid or base increases in strength, the strength of the conjugate acid or base decreases in strength. Furthermore, a greater $K$ value for an acid or base shows that the reaction is favored toward the right or toward the ionization of the acid. As a result, strong acids and bases almost completely ionize with a relatively large $K$ value.