Firework Research: A Twist on a General Chemistry Laboratory Practical

Résumé fourni par la source

Abstract Due to their striking colors and rapid progression, precipitation reactions and flame tests are two quintessential phenomena commonly showcased in general chemistry. This work presents a multipart experiment centered on these classic phenomena that is designed as a low-stakes midterm laboratory practical exam during a 150 minute laboratory period in the first semester of general chemistry. In an effort to reduce anxiety associated with high-stakes assessments and increase student enjoyment, this original laboratory practical exam has been reframed as a mini research project where students identify unknown metal salts that are used as firework colorants through flame tests, chemical color trends, and precipitation reactions. The experiment consists of six short parts that assess students’ understanding of various skills developed as part of a scaffolded curriculum in the first half of the laboratory course. The topics assessed include scientific vocabulary, glassware identification, Bunsen burner operation, stoichiometric calculations, standard solution preparation, qualitative observations, precipitation reactions, solubility, and gravity filtration. Instructional materials and information on implementation are presented. The efficacy of the experiment was shown by positive changes in student confidence and correctness when completing comparable questions over the course of the semester.

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