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 study aimed to investigate the effect of computer simulation and animation-integrated instruction on preservice science teacher trainees' conceptual understanding and retention of acid-base chemistry and stoichiometry. A quantitative approach with a pretest-posttest-delayed test quasi-experimental design was used. In the study area, there were…

Theoretical yield and extent of reaction (degree of completion) are important concepts in stoichiometry and in chemical kinetics. We provide expressions describing theoretical yield (Y) and maximum extent of reaction (fractional yield, f[subscript max]) for five examples of commonly encountered reversible chemical reactions: A [equilibrium sign]…

Students beginning college chemistry are expected to arrive prepared with fundamental, prerequisite conceptual understanding and skills from high school. While some topics may be reviewed explicitly in the course, prerequisite material-including hidden prerequisites often overlooked by faculty-is typically considered assumed prior knowledge and…

Over the past decade the Accreditation Board for Engineering and Technology, Inc. (ABET) has changed the general chemistry requirements to include a single introductory course for most engineering majors. There is a focus on outcomes that equip students with the ability to pass the Fundamentals of Engineering (FE) Exam and to work in…

High school students find reaction stoichiometry and the concept of the mole hard to comprehend. Teachers are well aware of the importance of teaching the mole concept and also the difficulty associated with it. In an attempt to improve the understanding of the mole concept with reduced difficulty, an atomic model kit that provides a hands-on…

Students who score within the bottom quartile on cognitive measures of math aptitude have been identified as at-risk for low performance in chemistry courses, with less attention as to "why" such differential performance persists. At-risk students struggle most differentially on assessment items related to the mole concept and…

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…

What evidence counts as teacher quality is a debate of continued interest to the teacher education community. Many education scholars have argued for the importance of retention of knowledge as an indicator of the quality of education acquired. This study explored the retention of the quality of planned Topic Specific Pedagogical Content Knowledge…

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…

The identification of students at risk for academic failure in undergraduate chemistry courses has been heavily addressed in the literature. Arguably one of the strongest and most well-supported predictors of undergraduate success in chemistry is the mathematics portion of the SAT (SAT-M), a college-entrance, standardized test administered by the…

Organic chemistry students struggle with multiple aspects of reaction mechanisms and the curved arrow notation used by organic chemists. Many faculty believe that an understanding of nucleophiles and electrophiles, among other concepts, is required before students can develop fluency with the electronpushing formalism (EPF). An expert concept map…

The study sought to find out difficulties encountered by high school chemistry students when solving stoichiometric problems and how these could be overcome by using a problem-solving approach. The study adopted a quasi-experimental design. 485 participants drawn from 8 highs schools in a local education district in Zimbabwe participated in the…