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 base0acid0

log base0acid0 = pH – pKa

base0acid0 = 10pH – pKa


nbase = V x [acid]0 x 10pH – pKa

nbase = 0.420 x 0.300 x 100.26

nbase = 0.229 moles