The conjugate acid acts as an acid, with a strength inversely proportional to the strength of its conjugate base. For example, since NH<sub>3</sub> is a weak base, NH<sub>4</sub><sup>+</sup> is a fairly strong acid. | The conjugate acid acts as an acid, with a strength inversely proportional to the strength of its conjugate base. For example, since NH<sub>3</sub> is a weak base, NH<sub>4</sub><sup>+</sup> is a fairly strong acid. |