Acids and Bases: Titration

The acid and base character of common products was to be investigated. Standard solutions of known pH had been prepared.

Red cabbage juice was one of the indicators used.

Samples included grape juice, beet juice, and vinegar above left. Samples were placed in individual compartments for testing.

With indicators, the pH of the samples could be bracketed.

For more precise pH determination, titration was to be used. Dr. Ellen Verdel demonstrates the use of the pipete and describes the process.

The point of completion of the titration process had to be approached carefully. A drop of the standard solution would turn the sample pink at the entry point, but would clear with stirring. At right above is a carefully determined final point with just a hint of pink showing.