Question

What is the pH of buffer solution formed by mixing 0.01 M acetic acid and 0.05 M sodium acetate? (pK_a = 4.7447)

Options

• 2.80

• 3.00

• 5.44

• 6.5

Answer 1

5.44

Explanation:

Henderson-Hasselbalch equation

\[\mathrm{pH=pK_a+log_{10}\frac{[Salt]}{[Acid]}}\]

\[=4.7447+\log_{10}\frac{0.05}{0.01}\]

= 4.7447 + log₁₀5

4.7447 + 0.7 = 5.4447