高等学校化学の知識・理解を総合的に活用するヒドロキシ酸の識別実験

抄録

This article presents a chemical experiment on the identification of hydroxy acids for high school students in order to elaborate their knowledge and understanding of organic chemistry. Four hydroxy acids, lactic acid, malic acid, tartaric acid, and citric acid were used for this experiment. By conducting several qualitative and quantitative analyses such as iodoform test, oxidation reaction, and neutralization titration, students could identify these hydroxy acids clearly. On the basis of the above findings, we propose two types of learning activities. One is a hands-on activity, through which high school students can develop a better understanding of property and reactivity of oxygen-function compounds when they have just learned a unit of organic chemistry. The other is an inquiry-based learning activity, in which students plan a protocol for experiment objectives, carry out the experiment, and draw a conclusion by combining experimental results with their knowledge. These activities are effective in improving not only conceptual understanding of organic chemistry but also scientific thinking and concerns about design, practice, and verification for chemical experiments.