Relational conceptual change in solution chemistry

Abstract

AbstractThis study explores changes to students' conceptions about solution chemistry in the context of instruction based on collaboration between a researcher and an experienced teacher attempting to implement strategies from the literature on conceptual change. Conceptual change for students and teachers is viewed not just as a process of replacement of old concepts but also as a process of learning to relate ideas to appropriate contexts. The process of instruction and collaboration was influenced by institutional limits on time, the press to cover the curriculum, and the teacher's prior beliefs and practices. The study uses “phenomenography” to conceptualize students' understandings of solubility. Six categories of description were constructed: (a) physical transformation from solid to liquid; (b) chemical transformation of solute; (c) density of solute; (d) amount of space available in solution; (e) properties of solute; and (f) size of solute. After instruction students showed evidence of two additional ways of talking about solubility: (a) chemical structure of components; and (b) solution equilibrium. The new language, however, did not necessarily replace initial ideas about what happens in particular instances of solution chemistry. A careful analysis of the students' conceptions of solubility revealed important factors influencing the nature of student learning in this area of chemistry. These factors include: (a) ambiguities of chemical theories about dissolving: (b) explanations of the observable; and (c) students' chemical language. It is argued, in conclusion, that the goals for instruction are to assist students to appreciate contexts where everyday conceptions of chemical phenomenon are appropriate and contexts where particular conceptions from the community of chemists are more appropriate. © 1995 John Wiley & Sons. Inc.