If a buffer solution is 0.530 0.530 M in a weak acid (K a = 7.1 * 10 - 6) (Ka=7.1*10-6) and 0.150 0.150 M in its conjugate base, what is the pH?

pH = 4.6

Explanation:

Given data

Concentration of the weak acid ([acid]) : 0.530 M Concentration of the conjugate base ([base]) : 0.150 M Acid dissociation constant (Ka) : 7.1 * 10⁻⁶

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

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

pH = - log 7.1 * 10⁻⁶ + log 0.150 M/0.530 M

pH = 4.6