# Exercise 2 | Buffers and Titration of Acids and Bases

How many moles of sodium acetate NaOCOCH3 must be added to 420 mL of 0.300 M acetic acid solution to produce a buffer with a pH of 5.00?

Data: pKa (CH3COOH/CH3COO-) = 4.74

Henderson-Hasselbalch equation can be used:

pH = pKa + log $\frac{{\left[\mathrm{base}\right]}_{0}}{{\left[\mathrm{acid}\right]}_{0}}$

log $\frac{{\left[\mathrm{base}\right]}_{0}}{{\left[\mathrm{acid}\right]}_{0}}$ = pH – pKa

$\frac{{\left[\mathrm{base}\right]}_{0}}{{\left[\mathrm{acid}\right]}_{0}}$ = 10pH – pKa

nbase = V x [acid]0 x 10pH – pKa

nbase = 0.420 x 0.300 x 100.26

nbase = 0.229 moles