Measuring Changes in Undergraduate Chemistry Students’ Reasoning with Reaction Coordinate Diagrams: A Longitudinal, Multi-institution Study

Abstract

The Reaction Coordinate Diagram Inventory (RCDI) was developed to measure chemistry students' thinking and confidence when interpreting the kinetic and thermodynamic information encoded within reaction coordinate diagrams (RCDs). The RCDI was designed based upon analyses of qualitative data collected in semi-structured interviews with general chemistry students or organic chemistry students to ensure all items and distractors were grounded in students' ideas and reasoning. A longitudinal, multi-institution research study was conducted using the RCDI to measure changes in undergraduate chemistry students' reasoning with RCDs, and their confidence in doing so, at three points in time: (1) end of secondsemester general chemistry, (2) beginning of first-semester organic chemistry, and (3) end of first-semester organic chemistry. The three institutions participating in this longitudinal study taught organic chemistry using either a traditional functional group curriculum or a mechanisms approach. Findings include evidence that individual students performed significantly better with significantly higher confidence as they progressed through courses, but that some RCD misconceptions, such as incorrectly assuming reaction progress indicates a time unit, are persistent throughout. Although two of the institutions taught organic chemistry using a mechanisms curriculum and one institution used the traditional functional group approach, no evidence exists of significant differences among students' RCDI total score and average confidence across institutions.

Students’ Strategies, Struggles, and Successes with Mechanism Problem Solving in Organic Chemistry: A Scoping Review of the Research Literature

“…Another challenge often faced by students is the need to consider and translate between the multiple representations of molecular structures and processes (e.g., IUPAC names, Newman projections, bond-line, EPF mechanisms, reaction coordinate diagrams), which can impact success in organic chemistry problem solving. ,,,, For instance, students in one study were more likely to arrive at the correct solution to organic chemistry problems (e.g., outline a synthesis, draw all possible isomers) when they drew more representations, including mechanisms . Despite the importance of multiple representations in organic chemistry, many studies show that it is challenging for students to translate between them (e.g., between different structural representations or between verbal and symbolic representations). ,, However, encouraging students to use models, especially physical models, can support their ability to translate between different structural representations (e.g., between Newman projections and bond-line structures). − A variety of studies focus specifically on how students consider reaction coordinate diagrams (RCDs) when solving mechanism problems. ,− Findings indicate that students often think that only the major reactants, intermediates, or products of mechanisms are depicted on RCDs . Additionally, students face challenges with connecting structural and energetic accounts of mechanisms (e.g., connecting mechanisms drawn with bond-line structures to RCDs), a task which is hindered when students are unable to propose reasonable reaction mechanisms. , The studies also demonstrate students’ difficulties with understanding the surface features of RCDs (e.g., the peaks, valleys, and axes). ,, …”

Impact of Clicker and Confidence Questions on the Metacognition and Performance of Students of Different Achievement Groups in General Chemistry

“…23 Furthermore, a longitudinal study found that students with more chemistry experience (some organic chemistry) were better calibrated, i.e., better at assessing their abilities, in their understanding of reaction coordinate diagrams than students with less experience (before organic chemistry). 24 An important consideration in these studies is that the selfassessment occurred during an exam or at the end of the semester, or after learning, study, and practice. In this study we were interested in the impact of students monitoring their understanding during learning, in a more formative fashion.…”

Trendbericht Chemiedidaktik 2021

“…62) Auch bei sehr gängigen Modellen wie Reaktionskoordinatendiagrammen (RCD) zeigte eine Längsschnittstudie Fehlvorstellungen selbst bei fortgeschrittenen Chemiestudierenden. 63) Besonders häufig können Studierende Intermediate und Übergangszustände nicht unterscheiden und interpretieren die Reaktionskoordinate fälschlicherweise als Zeitachse (Abbildung 6).…”