Journal of Chemical Education最新文献

As chemistry education researchers and practitioners continue to investigate and improve undergraduate laboratory courses, it is necessary to consider the perspectives held by each of the stakeholders who are directly involved in these courses, including laboratory coordinators, graduate teaching assistants, and students. This study sought to qualitatively investigate the learning goals and expectations held by laboratory coordinators, graduate teaching assistants (GTAs), and students for general and organic chemistry laboratory courses at a single institution. This was completed through the collection and analysis of semistructured interview data from laboratory coordinators and GTAs and open-ended written responses from students. Results indicated that while many of the learning goals and expectations were shared among the three groups, there were laboratory coordinator defined learning goals and expectations that were mentioned by very few or no GTAs and students. Additionally, the GTAs and students held expectations that were not described by the laboratory coordinators. The results of this study highlight the importance of explicit communication related to learning goals and expectations among laboratory coordinators, GTAs, and students involved in undergraduate laboratory courses. If the learning goals and expectations established by laboratory coordinators are not properly communicated to GTAs, then it is likely that these goals and expectations are also not being communicated to students, who bring in their own unique laboratory expectations based on their previous experiences and current beliefs.

The East Palestine, Ohio train disaster of February 2023 resulted from the derailment of dozens of train cars which leaked toxic chemicals, caught fire, and threatened the area with an explosion as a result of the possibility of polymerization of vinyl chloride. To mitigate the possibility of explosion, vinyl chloride was vented and burned from five train cars, resulting in a cloud of black smoke that could be seen and smelled for miles. An interrupted case study assignment based on the initial environmental and health concerns and data collected from air, water, and soil in the days following the disaster has been designed and implemented in an instrumental analysis laboratory course. While case studies are used frequently in business, medicine, and law, fewer case studies are found in the literature in the field of chemistry. Student work and survey data have been collected and analyzed, and findings suggest that this case study is effective at developing students’ problem-solving and critical thinking skills as well as fostering their ability to communicate scientific findings to nonscientists. Topics such as sampling, limit of detection, and instrumental methods are emphasized in the assignment. Student feedback suggests that the assignment allows students to better understand how analytical chemistry can be used in the real world, and students are highly responsive to the use of a real-world example for understanding analytical chemistry.

Learning the language of organic chemistry, i.e., how to describe reaction mechanisms, is crucial to success in any postsecondary organic chemistry course. However, it is well-known that learners struggle with reasoning about and explaining reaction mechanisms beyond surface-level features. Multiple studies have sought to aid learners in developing these skills. Investigating the connections that learners make regarding reaction mechanisms through their explanations provides insight into how we can better promote the development of learners’ reasoning skills. In this study, we evaluate 20,000+ learner explanations of 90 reaction mechanisms. We use network analysis to explore patterns in keywords used by learners and visualize the word connections between them, based on their co-occurrence, within our entire data set, by reaction type, and by levels of explanation sophistication. Our results indicate that learners consistently rely on explicit surface-level features in their explanations with expected contextual variance by reaction type. This trend persists across the levels of sophistication, however, with improvements in the use of vocabulary and coherency as sophistication progresses. We hypothesize that this is evidence of learners actively working toward constructing understanding as they experiment with and refine their vocabulary until they are able to pare down their explanations in a coherent manner. This work offers insights for instructors seeking to promote the development of learners’ reasoning skills and for researchers interested in the development of machine-learning models to assist in evaluating learner explanations of reaction mechanisms.

The chromatography method is deeply used in separation and analysis of organic compounds, and it is also an important element in organic chemistry experiment or advanced experiment courses. However, in undergraduate teaching laboratories, the number of liquid chromatography instruments is relatively limited, and most of the components of the instrument are enclosed in a box, which can not meet the learning and operating needs of all students. Thus, in our project, self-made low pressure liquid chromatography (SLLC) was designed and applied in an innovative experimental project to make sure that every student could build the device independently and use it to separate and detect chlorophyll and colorless conjugated organic mixtures. Gratifyingly, all students were interested in the experimental content. With the aids of hands-on activities and visually intuitive phenomena, the structure, principles, and operation of liquid chromatography (LC) can be fully understood and mastered. The project is suitable for promotion and practice in universities at all levels because it only took four credit hours and about 100 RMB (about 13 dollars) on the self-made SLLC.

The term “target fishing” refers to an experimental or computational approach to identify proteins that bind to a particular ligand or molecule of interest. This activity was designed for undergraduate students to explore the search for protein interactions to query molecules. The introductory phase of the project provides students with a general view of key concepts. Subsequently, the participants select a specific case study in which the target fishing technique had been previously applied. Each student analyzes in detail the context of the research, the molecules studied, and the proteins identified as potential targets. The activity seeks not only the practical application of theoretical concepts but also the development of research skills, the critical analysis of results, and participation in collaborative discussions on the relevance of target fishing. Through written reports, oral presentations, and classroom discussions, students will demonstrate their comprehensive understanding of this technique, their ability to contextualize it in real-world studies, and their ability to address issues associated with the application of the method. This project provides an interdisciplinary educational experience that integrates theory and practice, preparing students to understand and effectively apply the target fishing technique, as well as to recognize its limitations.

This research article aims to use Universal Design for Learning (UDL) and digital fabrication (DF) to create a tool for the inclusive teaching of chemistry, with the specific purpose of enhancing the teaching-learning process in organizing chemical elements. The Design-Based Research (DBR) methodology was employed. This methodology facilitated the design of a tool based on an alternative ordering to the traditional periodic table. Utilizing the principles of Universal Design for Learning and the implementation of digital fabrication technologies, especially 3D printing, it has been possible to link student-centered learning, inquiry-based learning, and hands-on learning. Experimental activities have been carried out with students and teachers from three schools in Catalonia, Spain, as well as validation with experts from the Spanish National Organization for the Blind (ONCE). The assessment discussion and analysis made by students, teachers and experts using mixed methods (quantitative and qualitative) is given. This research has exposed the synergy between universal design for learning and digital fabrication in learning and its contribution to improve the inclusive teaching-learning process.

We report an undergraduate, upper-division laboratory based on the synthesis of a stable, persistent organic free radical, TEMPO (2,2,6,6 tetramethylpiperidine-1-oxyl), and its characterization by electron paramagnetic resonance (EPR) and cyclic voltammetry (CV). The synthesis involves a three-electron oxidation of 2,2,6,6-tetrametylpiperidine by tungstate-catalyzed activated hydrogen peroxide. Students characterized their TEMPO by CV in our department, and we visited the University of Denver for the EPR characterization. Additionally, the TEMPO-catalyzed oxidation of a primary alcohol to the carboxylic acid in the presence of co-oxidants sodium hypochlorite and sodium chlorite was also investigated. This lab uniquely integrates key concepts and principles from both organic and physical chemistry, providing a comprehensive learning experience in upper-division instructional laboratories. This undergraduate lab is particularly relevant now, as the TEMPO radical is being used for the determination of local oxygen concentration in tumors, changes in redox status and radiation damage in cells, and in new battery technology. The four-part laboratory allows the flexibility of offering it in sophomore organic chemistry, physical/analytical chemistry laboratories or as an independent project for junior/senior level students over a 4-week period. Additionally, the four-part laboratory allows the flexibility of offering it in second-semester organic, physical, and/or analytical chemistry laboratories. Ultimately, this should serve as exemplary model for collaboration and cooperation between faculty at different universities with limited instrumentation.

Chemistry is often associated with formal learning environments and has been described as overly serious by the general public, lacking some of the fun and energy of other sciences. However, it is difficult to provide hands-on chemistry activities outside the lab and other formal learning environments. Here, a simple electrochemistry based activity has been used for public engagement using household items and play dough to create a fun and playful experience for all ages. The benefits afforded by outdoor learning for developing curiosity and interest in science has also been explored through different event formats. The use of a "Smiley Stand" with "emojis" for gathering participant feedback was successfully deployed alongside interviews with the "Ambassadors" who facilitated the activity. Overall, it was found that the activity encouraged two-way conversations between the participants and the ambassadors, with few negative responses and many positive ones received. The activity also impacted the ambassadors' own view of science.

At the nanometer scale, electrolyte solutions behave differently compared to their bulk counterparts. This phenomenon forms the basis for the field of nanofluidics, which is dedicated to studying the transport of fluids within and around objects with dimensions of less than 100 nm. Despite the increasing importance of nanofluidics for a wide range of chemical and biochemical applications, the ability to study this field in undergraduate laboratories remains limited due to challenges associated with producing suitable nanoscale objects. This article outlines a straightforward procedure, using easily accessible materials and chemical reagents, to create nanofluidic membranes, called nanowood, containing channels with diameters less than 100 nm. We describe the fabrication process of nanofluidic channels in wood and demonstrate the presence of these nanochannels based on conductance measurements using electrochemical impedance spectroscopy.

Molecular Structure and Organic Synthesis (MSOS) is an upper-division undergraduate (capstone) laboratory course for undergraduates majoring in chemistry at Xavier University of Louisiana (XULA). The course is designed for juniors and seniors and is based on self-regulated research and learning under limited instructor supervision. It includes a 2-step synthetic project, chosen by each student in the class from a list based on the Organic Synthesis periodical or actual faculty research and then carried out independently. In order to prepare students for their syntheses, we recently included a new project in the course syllabus focused on a reaction optimization that introduces the undergraduate students to the concepts of raising reaction yield, improving product purity, lessening the environmental impact of the reaction, and/or increasing its cost efficiency. A team of 2-3 students performs a preliminary experiment. A rerun by each individual team member incorporating his or her modifications follows this. The goal of this preparatory exercise is to enhance the students' soft skills, including teamwork, critical analysis of data, and scientific report preparation as well as develop a deeper understanding of the reaction mechanism to make calculated adjustments to reaction conditions for optimization.