If a buffer solution is 0.540 M in a weak acid (K a = 8.0 * 10 - 6) and 0.230 M in its conjugate base, what is the pH?

4.7

Explanation:

Given data

Concentration of the weak acid: 0.540 M Concentration of the conjugate base: 0.230 M Acid dissociation constant (Ka) : 8.0 * 10⁻⁶

We can calculate the pH of a buffer system using the Henderson-Hasselbalch's equation.

pH = pKa + log ([base]/[acid])

pH = - log (8.0 * 10⁻⁶) + log (0.230 M/0.540 M)

pH = 4.7