Design and development of a computer learning environment on the basis of students' initial conceptions and learning difficulties about chemical equilibrium

This paper describes the design and development of an interactive learning environment inspired from the constructivist view of learning and aiming at helping students improve their conceptions about chemical equilibrium. The design of the software was based on data that emerged from research we undertook with 175 Greek students (aged 17-18), in order to detect their conceptions and learning difficulties about chemical equilibrium. The students' answers to a written questionnaire showed that they had inadequate representations of systems of substances at chemical equilibrium related to the empirical and the atomic level, manifested serious difficulties in conceiving the initial situation of a system at chemical equilibrium and the equilibrium shift, made overextended use of the Le Chatelier principle and applied intuitive personal rules instead of the equilibrium constant law. The aim of this computer application is to help students to create and/or improve their own representations about substances at chemical equilibrium in the empirical, atomic and symbolic level, to establish appropriate links among these multiple representations, and to construct appropriate conceptions about the Le Chatelier principle and the equilibrium constant law. The software contains simulations and visualizations of experiments representing systems at chemical equilibrium, simulations of chemical reactions related to the atomic level, symbolic representations and dynamic graphs, and a step-by-step derivation of the equilibrium constant law. © 2001 Kluwer Academic Publishers.