A brief review on the contribution to the knowledge of the difficulties and misconceptions in understanding the chemical equilibrium.

The existence and persistence of errors in the understanding of chemical equilibrium denotes student"s difficulties in learning and also in teaching methodologies. The knowledge of these difficulties, in depth, can help teachers to try to overcome them. This work is a review together with new contributions on the chemical equilibrium misconceptions analyzed by a group of university and high school teachers. On the one hand, we pretend to collect some of most common difficulties that students, from high school and university, show in re lation to chemical equilibrium and Le Chatelier's Principle application. On the other hand, we also intend to analyze the possible causes and even, ocasional…