Diagnosing Students' Misconceptions On Solubility And Saturation For Understanding Of Phase Diagrams

Abstract

Students in introductory chemistry classes often harbor or develop misconceptions about solubility concepts of solutions that inhibit their ability to understand of the nature of solution behavior. Subsequently, when these prior misconceptions are carried over into introductory materials engineering classes, they also inhibit students' ability to understand the liquid and solid solution concepts necessary to effectively understand and use phase diagrams. The end result is that students may never fully comprehend and appreciate the relationships between phase diagrams, materials' microstructures and associated correlations to materials' properties. This research, which is associated with misconceptions revealed from a Materials Concept Inventory (MCI), has investigated students' understanding of concepts of solubility and saturation that are associated with liquid and solid solution behavior necessary to understand phase diagrams. Student knowledge of solution behavior was studied with two-tiered questions. For the first tierquestion students chose a schematic diagram that represented the solution characteristics that portrays their mental model about some aspect of solution behavior. In the second-tier response students then described the reason for their choice of a given diagram for the first-tier question.