Playing Around with “Kaleidagraph” Program for Determination of pK_a Values of Mono, Di and Tri Basic Acids in a Physical-Organic Chemistry Laboratory

A simple and easy laboratory protocol for the determination of the pK_a of mono, di and tri-basic weak acids is described in this paper by using arbitrarily simulated data as a function of pH. An equation compatible to Kaleidagraph program is derived and used in the program to determine the pK_a. The present protocol for the determination of the pK_a is useful in teaching chemistry experiments in a Physical-Organic Chemistry Laboratory.