Stoichiometry has always been a puzzling subject. This may be partially due to the way it is introduced to students, with stoichiometric coefficients usually provided in the reaction. If the stoichiometric coefficients are not given, students find it very difficult to solve problems. This article describes a simple 4-h laboratory experiment for…

This paper includes two experiments, one investigating complexity factors in stoichiometry word problems, and the other identifying students' problem-solving protocols by using eye-tracking technology. The word problems used in this study had five different complexity factors, which were randomly assigned by a Web-based tool that we developed. The…

The study focuses on percarbonate-based stain removers since the percarbonate can be heated to produce additional sodium carbonate. An experiment that provides general chemistry students an opportunity to apply their knowledge of basic stoichiometry to solve a relevant, real-world problem is described.