Traditional chemistry courses primarily focus on building content knowledge. However, recent movements in science education place large emphasis on students using their content knowledge to predict and explain phenomenon at the molecular level. In this study, we investigated how students used graphical models to predict changes in concentration of reactants in reactions carried out at different temperatures. We interviewed fifteen undergraduate general chemistry students using a semi-structured interview protocol. During interviews, students explained their reasoning as they constructed graphical predictions for what would happen to concentration of reactants at different temperatures. Using an inductive analysis, we focused on characterizing the nature of students’ claims and reasoning while making their predictions. We found that although verbal and graphical claims (what they drew) were similar for most students, reasoning and evidence used to support their claims varied widely. For example, some students relied on conventional wisdom that things get faster as they get hotter (lower level of sophistication) while others referenced an increased number of successful collisions per unit of time (higher level of sophistication). From this analysis we have developed a detailed characterization of students' responses in terms of increasing sophistication of evidence and reasoning. This characterization can be used to better understand student’s reasoning related to graphical models of reaction rate and to provide a foundation for evidence-based improvements to assessment and curriculum.

Characterizing students’ reasoning about graphical models of reaction rate

251st National Meeting (2016)

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