Blue Bottle Experiment: Learning Chemistry without Knowing the Chemicals

The blue bottle experiment is a popular chemical demonstration because of its simplicity and visual appeal. Most papers on the topic focus on a new formulation or a new presentation, but only a few discuss pedagogical application for a full lab session. This article describes the use of this experiment in the first session of undergraduate chemistry laboratory at the Mahidol University International College: Practical activities are designed to foster critical thinking and student-centered learning during a four-hour lab session. The main theme of our teaching is scientific method. Students are encouraged to work with a peer to propose hypotheses and test them. With a series of guidances and hints from the instructor and group discussion, students can propose the reaction mechanism for the experiment without knowing the identity of the chemicals in the reaction. Procedures described in this article may be used elsewhere with minimal modification