Are you teaching “distillation” correctly in your chemistry classes? An educational reconstruction

Distillation is often taught at secondary level in chemistry classes. There are, however, several pitfalls in teaching and learning the topic. First, there is not enough accessible research on students’ conceptions regarding distillation, which makes it difficult for teachers and teacher educators to teach accordingly in school or university. Second, the scientific explanation of distillation, especially the separation of liquid-liquid mixtures, is much more complex than represented in school books or other learning material. Third, teachers understandably rely on the representation in school books and other materials when teaching distillation, so that inappropriate concepts may be transferred to students. In this article, we follow the model of educational reconstruction and illustrate with reference to chemistry textbooks, school books, our own research results, and other studies on students’ conceptions the three pitfalls named above. Thus, this article aims to provide support for teachers and teacher educators to structure lessons on distillation based on scientifically appropriate information and with regard to students’ conceptions.