Historical approach to the principle of le Châtelier: acceptance, questioning, teaching problems and learning difficulties. Didactic implications

Abstract

A historical study is carried out on Le Châtelier’s principle. After its first acceptance, the principle was widely questioned because of both its limitations and the vague and ambiguous character of the different attempts performed to qualitatively enunciate it. New criticisms emerged to the various rules that have been formulated for educational purposes. Apart from this, it is usually presented as a universal rule, easy to remember and apply, which may explain why it has been consolidated as a didactic tool within the topic of chemical equilibrium, which has led to be one of the essential elements for its assessment.