Journal of Chemical Education最新文献

Traditional approaches to the chemistry curriculum for undergraduate students prioritize coverage of fragmented individual topics rather than employing systems thinking to embed chemistry concepts in immersive holistic contexts vital to our planet’s future, such as climate change. Many students are eager to understand and tackle climate change, drawing on political, socioeconomic, sustainability, and chemistry perspectives. However, educators face substantial barriers in resourcing climate empowerment through chemistry education. This paper outlines interactive resources and activities educators can use to help students engage with climate literacy and action, grounded in an emerging understanding of key concepts in chemistry. These resources draw from the work of 14 third- and fourth-year undergraduate students at The King’s University who were learning about climate change in an environmental chemistry class. The students, who also coauthored this paper, collaborated in small groups and as an entire class to develop learning activities, pilot activities created by others, articulate topics for educators, and perform several rounds of peer review. Together, the students developed activities and learning outcomes that they hope others will use to connect climate change to cognitive, affective, and kinesthetic learning in chemistry.

The microstates of an isolated system indicate the different distributions of the energy of a system over the set of particles of the system. Microstates with the same (quantum states) occupation number form a configuration set. All microstates have the same probability of occurrence. Students determined the probability distribution of the configurations in a model experiment demonstrating the ergodic theory. The model experiment required a volumetric flask with white and blue plastic balls. The sequential order (repeated permutation) of the plastic balls in the neck of the flask corresponds to a microstate. The experiment was performed after the theoretical lecture.

Students’ scientific competencies can be improved by structured inquiry. Inquiry teaching laboratories that involve thin-layer chromatography (TLC) techniques most often involve students examining experimental results. In addition to the integration of structured inquiry into the teaching laboratories of TLC, this quasi-experimental study involved students in reflection on experimental procedures. We aimed to investigate the impacts of this combination of structured inquiry and reflection (i.e., reflective inquiry) on students’ chemical explanatory levels. A total of n = 107 11th grade students participated in this study. Students in the experimental group (EG; n = 58) engaged in a 10-week reflective inquiry while students in the comparison group (CG; n = 49) engaged in confirmation inquiry. Results showed that reflective inquiry enhanced students’ explanations at the experiential level. At the theoretical descriptive level, students displayed misconceptions or misinterpretation of scientific concepts. Furthermore, presenting the dynamic interactions within the TLC system at the theoretical explanatory level was challenging to students. The TLC assessment can provide chemistry teachers with the opportunity to diagnose students’ misconceptions of the TLC system at both the experiential level and the theoretical explanatory level.

A simple and durable luminescent powder can be conveniently prepared by mixing washing powder, luminol, and potassium hexacyanoferrate(III) to carry out impressive chemiluminescence experiments. The students particularly enjoyed using the mixture in a light-colored painting activity. In addition, various washing powders, brought from home by the students, can be tested indirectly for the presence of oxygen-based bleaching agents via their “luminosity”. The luminescent powder offers many starting points for lessons on the topics of reaction energy, light, and oxygen, combined with a playful fun factor, and is suitable as a motivating introduction or as a school experiment.

Reaction mechanisms are a difficult and foundational topic students encounter in organic chemistry. Consequently, students often memorize when attempting to learn the array of organic reactions. While interventions have been offered to encourage mechanistic reasoning as an alternative approach, a deeper struggle pertaining to students’ comprehension of the underlying chemical principles driving reaction mechanisms is still prevalent. In this study, electrostatic potential maps (EPMs) were explored as a tool students could use to reason with some of these principles to predict and explain the outcomes of a reaction. Through semistructured interviews, 19 students’ sense-making strategies were recorded and analyzed to uncover how they used the features of EPMs with concealed atomic identities and how they reconciled their answers once the identities were made explicit. Analysis revealed that the absence of atomic identities generated approaches centered around electron densities and their utility in predicting reaction mechanisms and outcomes. As the atomic identities were revealed, the majority of participants reverted to memorized mechanisms, while six participants attempted to relate the atomic identities to the interactions of the electron densities. These findings suggest utility in implementing EPMs in the organic chemistry curriculum and offer a feasible intervention to promote sense-making when students reason with organic reactions.

Educational experiments that spatially visualize chemical reactions in hydrogels have been developed and demonstrated, taking advantage of the slow diffusion in hydrogels. A solution containing a reactant was diffused into a hydrogel containing a counter-reactant, resulting in a color change. The distance of the color change depended on the concentration of the reagent, which is beneficial for quantitatively observing the degree of the chemical reaction. First-year university students performed the experiment with interest and demonstrated good learning outcomes. The demonstrations shown in this study, along with the failure cases, will serve as guidelines for visualizing other chemical reactions in hydrogels.