Consider a buffer solution containing a weak acid, HX, and a salt of the weak acid's conjugate base, NaX. Under what conditions does the pH just equal the p K _a of the weak acid?

Question

Quizplus · Accepted Answer

When [HX] = [NaX], the concentration of the weak acid and its conjugate base are equal, resulting in the buffer solution being at its optimal buffering capacity, and the pH being equal to the p K _a of the weak acid (assuming ideal conditions with no complications such as any common ion effects).

Consider a Buffer Solution Containing a Weak Acid, HX, and a Salt