Question

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?

Answer 1

Answer:

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