Acid-base titration curves in an integrated computer learning environment

Abstract

The topic of acid-base reactions is a regular component of many chemistry curricula that requires integrated understanding of various areas of introductory chemistry. Many students have considerable difficulties understanding the concepts and processes involved. It has been suggested and confirmed by research that students may benefit from computer-supported activities such as data logging, simulation and modeling. In this paper we review the different methods of using computer acquisition and modeling to examine acid-base titration and we discuss how a versatile, integrated computer learning environment can be successfully applied to this end. The environment integrates, amongst other things, measurement, a control tool, and a modeling tool: using an inexpensive step-motor buret, automated pH measurement in acid-base titration can be realized and measured data can then be compared graphically and in tabular form with data computed via the (text-based or graphical) system dynamics modeling tool. In this paper we discuss concrete examples, taken from an in-service teacher training course and culminating in the student practical investigation of analysis of acid in soft drinks. We also show how computer algebra can assist to find the mathematical formulas needed for computing a titration curve. We discuss the design of instructional materials and the didactical approach of integrating data logging and modeling in acid-base chemistry education.