Teaching Acid-Base Equilibria by Using Log-log Diagrams

Abstract

The purpose of this column consists in illustrating the utility of log-log diagrams for the graphical determination of the pH value of acid-base systems in dilute aqueous solution. This methodology allows to tackle systems going well beyond the case of mono- or diprotic acids, providing fast and accurate estimations of the pH. It is also argued that the use of so-called Sillén diagrams affords a better understanding of complex acid-base systems.

Keywords

• Acid-base equilibria
• Distribution diagrams
• Sillén diagrams
• Graphical pH determination