In chemical synthesis, obtaining product(s) with high purity is a crucial issue from both academic and industrial viewpoints. Higher purity of the product(s) means higher quality and a lower chemical production costs. Sometimes, purification and separation processes are very laborious and lead to significant impacts on the final price of the…

High school students and students in the first years of college have difficulties in understanding the topic of stoichiometry and, in particular, the concept of limiting reactant. Proposals aimed at overcoming these learning obstacles tend to focus on analogies, and there are few sequences that approach teaching from an experimental perspective.…

The pharmacologically active lignans sesamin and sesamolin are minor components of sesame oil and ingredients in OTC dietary supplement capsules. We report an introductory undergraduate organic laboratory experiment combining natural product isolation and spectral analysis in which students isolate a mixture of sesamin and sesamolin by either (1)…

The basic knowledge of chemical formula writing is fundamental for chemistry students, yet many still struggle to learn it. To provide a more interactive and engaging approach that facilitates and reinforces student understanding of chemical formulas and stoichiometry of chemical reactions, we have designed a chemical jigsaw puzzle. Only eight…

This is an easy and inexpensive laboratory experiment in which undergraduate students at the Bachelor's degree level in Chemistry can measure formation constants of complexes [Ni(en)[subscript n](OH[subscript 2])[subscript 6-2n]][superscript 2]+ (n = 1, 2 or 3; en = ethylenediamine) through an acid-base titration. The background information…

The paper presents the design and evaluation of a voluntary online introductory stoichiometry (VOIS) course aimed at facilitating the transition from secondary to higher education. The course utilized simple analogies and adaptive feedback through a formative scaffolding assessment. The study assessed the effectiveness of the VOIS course through…

This article presents and discusses the results of an educational innovation that seeks to introduce the world of molecular gastronomy in chemistry lessons as a means to review stoichiometry and offer an alternative way to learn. In the literature to date, there is no evidence of haute cuisine having been employed to contextualize stoichiometry…

The purpose of this randomized experimental study is to apply two socio-cognitive models to understand possible ways to improve students' learning outcomes in an online introductory chemistry learning environment. Specifically, the social presence theory suggested that students' sense of relatedness and learning motivation can be increased by a…

Emphasizing stoichiometry appears to be a norm of introductory chemistry courses. In this longitudinal and mixed-methods study, we examined how the emphasis on stoichiometry in assessments of introductory chemistry impacted educational equity and student learning. Using quantitative methods, we identified mole and stoichiometric conversions as two…

Learners underperform in stoichiometry as they lack conceptual reasoning of the underlying concepts and the ability to solve stoichiometric problems. Therefore, it was necessary to determine if there is a statistical correlation between problem-solving skills and conceptual reasoning in stoichiometry and if so, whether one can significantly…