Blue Bottle Experiment: Learning Chemistry without Knowing the Chemicals

Abstract

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.

A DFT investigation of the blue bottle experiment:E∘half-cellanalysis of autoxidation catalysed by redox indicators

“…The solution is blue and is not reduced to colourless over time. — Replacement of dextrose by acetoin and dihydroxyacetone in the blue bottle experiment yields repeatable colour change and chemical patterns [ 18 ]. Phenol-derivatives such as catechol reacts with oxygen rapidly under alkaline conditions without a dye to produce a dark-coloured solution.…”

“… Alternative reducing agents such as amino acids may also be used in the blue bottle experiment. — Replacement of dextrose by amino acid and various food products yields repeatable colour change but some of the reactions are slow [ 18 ]. — In an iodine clock experiment [ 60 ], cysteine is also used successfully in place of ascorbic acid.…”

“…— Replacement of dextrose by amino acid and various food products yields repeatable colour change but some of the reactions are slow [ 18 ].…”

“…The blue bottle reaction and its analogues are popular chemical demonstrations due to their visual appeal and simplicity, and the majority of the research on this topic is published in the Journal of Chemical Education [ 1 – 18 ]. Fundamental research and non-education applications of the reactions have also been discussed elsewhere [ 19 – 26 ].…”

Chemical Patterns in Autoxidations Catalyzed by Redox Dyes

“…In our context, this inquiry-based laboratory is given at the very last week of the first chemical laboratory course for undergraduate students. Our students have had prior knowledge of the reaction by completing the first four activities of the blue bottle experiment (see ref (5)’s Supporting Information) in one of the previous lab sessions. Students work in groups because of the nature of the work that required simultaneous mixing or transferring of chemicals and limited lab space/equipment.…”