El razonamiento causal secuencial en los equilibrios ácido-base múltiples : propuestas didácticas en el ámbito universitario

Abstract

The need to control several equilibria simultaneously is the main difficulty met by students when they approach multiple acid-base equilibria. Presenting beforehand these equilibria to secondary school students encourages the use of causal sequential reasoning that takes processes not as equilibria but isolated, without simultaneity, each process being the cause of the former and causing the following. In this article, on the one hand we diagnose the alternative conceptions related to multiple acid-base equilibria. On the other hand we propose to improve learning by using problem solving and the computer as an auxiliary resource. We previously analyse the wording of the problems presented in some university textbooks as starting point to our didactic proposal, which asks the students to explain all the equilibria in multiple acid-base processes as part of a heuristic for problem solving and to use the computer to solve mathematical difficulties, giving priority to the analysis of the chemical process.