Answer:
You need to add 19,5 mmol of acetates
Explanation:
Using the Henderson-Hasselbalch equation:
pH = pKa + log₁₀ [base]/[acid]
For the buffer of acetates:
pH = pKa + log₁₀ [CH₃COO⁻]/[CH₃COOH]
As pH you want is 5,03, pka is 4,74 and milimoles of acetic acid are 10:
5,03 = 4,74 + log₁₀ [CH₃COO⁻]/[10]
1,95 = [CH₃COO⁻]/[10]
<em>[CH₃COO⁻] = 19,5 milimoles</em>
Thus, to produce an acetate buffer of 5,03 having 10 mmol of acetic acid, you need to add 19,5 mmol of acetates.
I hope it helps!
