Chemistry: Interactive pH Titration

Objectives

• Students will observe how the features of a weak acid-strong base titration curve change when varying the acid ionization constant and/or the concentrations of the weak acid and strong base.
• Students will determine an equation for the volume of base added at the equivalence point.
• Students will relate pH to pKa at the "halfway" point in a titration. They will see that pH changes slowly with volume of base in the region around the halfway point. This is the buffer region.

Vocabulary

• acid ionization constant
• buffer
• equivalence point
• halfway point
• pH
• pKa
• titration curve

About the Lesson

This lesson features an interactive titration curve for a weak acid-strong base titration.
As a result, students will have a better understanding of:

• How acid concentration, acid ionization constant, and base concentration affect the titration.
• The pH of a weak acid is not 7.0 at the equivalence point.
• The pH at the halfway point is equal to the pKa of the acid.