Applying Le Chatelier’s Principle To Model Strong Acid–Strong Base Titration

摘要

Le Chatelier’s principle is used as a basis to derive an expression to calculate solution pH during titrations that involve only strong acids and strong bases. Central to this model are the reaction quotient and a re-equilibration term that represents the extent of neutralization during a titration. Unlike the method traditionally taught to students to determine the pH of these acid–base mixtures, the expression obtained is exact and applies throughout the entire range of a titration curve without the need for modification or segmentation. The expression is the same as one that is obtainable using charge balance; however, the present derivation applies Le Chatelier’s principle instead, and therefore remains within the scope of a general chemistry curriculum. Instructors are then able to reinforce and deepen understanding of previously learned concepts in acid–base chemistry while connecting them to chemical equilibrium and titration curves.