This study examined two assessment approaches—a case comparison prompt and a reasoning chain construction task to elicit students’ knowledge and application of green chemistry within the context of SN1 and SN2 reactions. The case comparison prompt presented students with a context-specific evaluation of two reactions, whereas the reasoning chain construction task required a general comparison of SN1 and SN2 reactions. Following each open-ended assessment, students were asked to select a conclusion regarding the overall greener reaction. The assessments were administered as an online survey, and student responses were analyzed using the twelve principles of green chemistry. Analysis of student responses showed that students consistently selected the same reaction type across assessments despite differences in task format. Across both assessments, students most frequently prioritized the use of safer solvents over considerations related to stereochemical outcomes, leading them to identify the SN1 reaction as the greener option. Overall, this study reveals how students apply green chemistry considerations to organic reactions across two open-ended assessment formats and demonstrates consistent patterns in their conclusions despite differences in the assessment formats. Importantly, the findings also revealed alternative lines of reasoning and misconceptions that are not readily captured by closed-ended assessments alone.
Ajayan et al. (Sat,) studied this question.