An investigation into chemical engineering students' understanding of the mole and the use of concrete activities to promote conceptual change

Abstract

First year chemical engineering students' understanding of the mole was investigated and an intervention designed to improve their grasp of this fundamental concept. Students' ideas were initially elicited in a series of group interviews. These findings were checked against a multiple-choice test which was developed and administered to the whole class. The intervention comprised a series of activities with a focus on ‘tangible objects’ which could provide students with a visual/experiential point of reference. Both qualitative and quantitative assessments indicated a strong positive effect of the intervention. This approach now forms part of the first year curriculum at the University of Cape Town. Although these students' problems were focused on the concepts of gmol, lbmol, and kmol, the misconceptions identified were found to link strongly to those previously reported in the literature for gmol, which suggests a broad applicability of the results obtained.