This page explains the different responses to adding HCl to pure water versus a solution with acetic acid and sodium acetate. It describes how buffers, like the acetic acid-sodium acetate mixture, res...This page explains the different responses to adding HCl to pure water versus a solution with acetic acid and sodium acetate. It describes how buffers, like the acetic acid-sodium acetate mixture, resist changes in pH due to their equilibrium shifting. The Henderson-Hasselbalch equation is central to understanding buffer preparation and effectiveness.