2011 Volume 51 Issue 3 Pages 159-167
We developed teaching materials on separation and purification of mixtures that students could use to make experiments using their own materials individually. In chemistry textbooks for upper secondary school, the experiments of filtration, distillation, sublimation, extraction, recrystallization, and chromatography were introduced as a way to separate and purify mixtures. Whereas government guidelines for teaching in upper secondary school mention the necessity of experiments, it is difficult to make them because of lack of time, costs, and preparation and sequencing difficulties. In this study, we made teaching materials based on a microscale experiment of separation and purification of mixtures, using small size test tubes, electronic balances, and experimental gas ranges. We were able to do several experiments within a limited time by using microscale experiment teaching material. Individual experiments were more effective for developing students' understanding of chemical properties of matter than group experiments are. With developed teaching materials, we taught upper secondary school students. In a hundred minutes, students did six experiments using their own materials. The amount of waste fluid decreased down to about one-tenth of ordinary scale experiments. The analysis of a questionnaire in case of the trial for upper secondary school students confirmed that it is important to make individual experiments when students learn separation and purification of mixtures.
