Hands-on learning of chemistry concepts

Abstract

Background – Stoichiometry is among the most difficult chemistry concepts to teach and it is often taught with an emphasis on algorithmic understanding, without emphasis on conceptual understanding. The purpose of this study was to ascertain if the use of dynamic submicro representations via hands-on learning activities, comprising molecular models and molecular graphics, can provide positive insights into students’ understanding of stoichiometry. Methods – An action research was carried out involving two cycles of lessons i.e., cycle 1 with “static” submicro representations (PowerPoint) to teach stoichiometry and cycle 2 with “dynamic” submicro representations (hands-on learning with molecular models and graphics) to teach stoichiometry. To gather data, these instruments were used: (1) a stoichiometry test with structured questions, (2) students’ activity journals and (3) open-ended semi-structured interviews. Results – This study indicated that students who had learnt stoichiometry with only “static” submicro representations, faced difficulties in understanding stoichiometry at the submicro level. This study also showed that students can benefit from the use of “dynamic” submicro representations (hands-on learning activities) in understanding stoichiometry at the submicro level. Positive changes in students’ understanding were categorised as a change from a ‘Lack of understanding’ to ‘Correct understanding’. This was determined from transcribed data obtained from the interview sessions and the students’ activity journals. Conclusion – This study provided evidence that the use of “dynamic” submicro representations can foster conceptual understanding of stoichiometry at the submicro level. As the local context of the study undertaken by the researcher was the prevailing factor that made this action research unique, the scope of the research and the pedagogical restrictions encountered by the researcher were considered the study’s limitations. The uniqueness of this study lies in its approach of involving hands-on learning activities in lessons on stoichiometry.