High School Students' Representations of Chemical Equilibrium

Meaningful learning resulting from laboratory instruction has been a recurring area of research for science teachers and students at all levels. Likewise, chemical equilibrium is considered to be one of the most difficult concepts to teach and demands the mastery of a large number of related concepts. Therefore, we investigated how laboratory instruction about chemical equilibrium might help students to construct and apply meaningful mental models of macroscopic, molecular, and symbolic representational levels. In this study, high school student-constructed concept maps (n= 9) that emerged from pre- & post- laboratory instructional interviews about chemical equilibrium were scored against an expert map using a rubric. We used these student-constructed concept maps in conjunction with the interviews as way to provide a 2D-representation of (1) the students’ knowledge about chemical equilibrium and (2) the students’ use of the three representational levels. A scoring rubric was developed to (1) qualitatively describe the concept map configuration, (2) quantitatively analyze the accuracy of the links, and (3) classify the links on the map based on three representational levels. Interrater reliability for the scoring scheme was high (r= 0.82). The student-constructed concept maps proved to be an excellent tool for students to generate meaningful connections between chemical equilibrium concepts. Results revealed that the students did make at least some use of each of the three representational levels. Main findings of this study and implications for teaching will be presented.