Las representaciones de los estudiantes sobre el concepto de concentración de disoluciones

Abstract

The concept of solution concentration is basic in the experimental sciences; however, it has not been addressed in depth by educational research. This article presents a review and discussion about the investigations that have been carried out regarding the students’ internal representations of the concept of concentration, which used situations with particle diagrams. It also analyses the representations evoked by 36 first-year university students, in interviews with the thinking-aloud protocol, when they solve a questionnaire. The questionnaire inquires about the relationships between the variables involved in the definition of concentration. The results show that: (a) particle diagrams can be useful for teaching and evaluating students' conceptions if a series of limitations are taken into account and (b) the interviewed students resort to different representations referring to macroscopic objects, properties or processes and not submicroscopic particles. Finally, implications for teaching are shared.