Mechanism comics as a task in a written exam in organic chemistry for pre-service chemistry teachers

Abstract

In this paper, we describe and evaluate a study on the use of mechanism comics for writing solutions to a task in a written exam for the course "Organic Chemistry I for Pre-Service Chemistry Teachers."The students had to design a reaction mechanism for a reaction that was unknown to them and write captions explaining every step of their reaction mechanism. The students' work was evaluated using the method of qualitative content analysis in four rounds by both authors. The majority of the captions were coded as "descriptive"and only a minority as "causal."This means that the students mostly described "what"happened, but seldom "why"this happened. Implicit electron movement was also described more often than explicit electron movement. The majority of the captions were technically correct. In summary, the students were capable of designing and describing a reaction mechanism for a previously unknown reaction. The quality of their reasoning could be improved, however. In the new course, the quality of students' mechanistic reasoning and then especially their explanations of "why"mechanistic steps occur will be given much clearer emphasis.