Journal of Chemical Education最新文献

The yellow–blue color pair has been used in creative artwork such as paintings and designs and in color engineering. Herein we present a method for using the yellow–blue combination in a chemistry lesson dealing with π-conjugated molecules for first-year undergraduate students who are not science majors. The lesson begins with an introduction to primary yellow compounds that contain π conjugation within their molecular structures and a demonstration of yellow dyeing using gardenia fruits or marigold petals. In addition to an overview of various yellow compounds, blue compounds with π-conjugated molecular structures are presented to enhance the perceived aesthetic stimulus. Yellow luminescence, blue luminescence, and intramolecular and intermolecular chemical reactions to produce yellow and blue compounds are exhibited. Through these demonstrations, students learn about basic π-conjugated molecular structure.

Amidst ongoing attempts to enhance green chemistry education in the chemical sciences curriculum, the teaching of analytical methods, such as spectroscopy, still largely lacks grounding in the principles of green chemistry. In an attempt to embed this context to spectroscopy education, this article describes the development, delivery, and evaluation of a course module designed to teach spectroscopic methods within the context of pollution analysis. Using the Integrated Course Design framework, a course section that intertwines fundamental spectroscopy knowledge with the application to pollution analysis was developed. Following the design and delivery of diverse teaching and learning activities, the analysis of student feedback revealed a high degree of satisfaction with the course. Some reservations around digital learning resources and group work activities present scope for improvement. This paper also describes the use of a multifold student assessment model developed on the basis of spaced repetition learning.

While students can learn both chemistry content and inquiry practices by participating in course-based undergraduate research experiences (CUREs), it is well documented that prior experiences shape perception. We conducted a case study to investigate students’ first experiences with a CURE in an upper-division chemical engineering laboratory course, drawing upon interviews (n = 6), field notes, and written reflections (N = 31). We used discourse analysis to characterize students’ agency as they navigated their uncertainty and made sense of the authentic research. We found that students’ past experiences shaped their expectations about the CURE, with some wishing for traditional learning supports misaligned to CUREs. Offering students constrained yet consequential agency allowed them to recognize the authentic supports that were available, including help-seeking as itself a form of agency; understand failure as endemic to research rather than their own shortcoming; and position themselves as capable of navigating the uncertainty as a community of researchers. Our results suggest that instructors should model uncertainty and failure as endemic to research and position students as valued collaborators and support for overcoming abundant prior experiences with cookbook-style experiments.

Women, ethnic minority, and less affluent groups are widely underrepresented in chemistry, a problem that is observed at all levels but begins before college matriculation takes place. The importance of representation and humanization of scientists is crucial. Despite limited progress over recent decades, poor visibility of role models from underrepresented groups remains problematic, emphasizing the importance of initiatives to positively introduce them in classroom settings. Through profiles of underrepresented “success stories” from academia and industry, the ChemDiverse project was developed to encourage underrepresented groups to pursue the chemical sciences at higher education levels by providing teachers with an easy and structured way of encouraging Scottish high school students into science, technology, engineering, and mathematics (STEM). Based on survey feedback from teachers at participating schools, it is a well-formulated project that is easy to implement within the context of the Scottish Curriculum for Excellence.

Nanozyme is a kind of mimetic enzyme possessing unique properties of nanomaterials and catalytic functions of natural enzymes. The nanozymes have the characteristics of high catalytic efficiency and good stability and are widely utilized in medicine, chemical industry, food, agriculture, and environment. This laboratory experiment is designed for third-year undergraduate students who have a background in chemistry or material science. The experiment involves the synthesis, characterization, catalytic performance, and application of copper doped cerium oxide nanoparticles (Cu-CeO₂ NPs), which contain both CuO and CeO₂. The required raw materials for the experiment are readily available, and the synthesis process is safe and simple. The nanomaterials are characterized via transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–vis spectroscopy. The experiment also involves studying the peroxidase (POD)-like activity of Cu-CeO₂ NPs, which catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) into its oxidation state in the presence of H₂O₂. In the presence of Cr(VI), the Cu-CeO₂ NPs-based colorimetric reaction was enhanced and also increased with the concentration of Cr(VI). This can be used for the sensitive detection of Cr(VI), which was much better than that without Cu-CeO₂ NPs. This laboratory experiment provides the third-year undergraduates with a chance to enhance their knowledge in advanced nanomaterials and modern characterization instruments. Additionally, it helps students to develop their hands-on operation skills, team cooperation ability, and the ability to integrate theory with practice.

Previous educational articles on microfluidic technology mainly focused on continuous microfluidics, so we set up an undergraduate laboratory experiment to introduce droplet microfluidics to students. Students can understand the concept of microfluidic channels and the principles of droplet microfluidics, prepare polydimethylsiloxane (PDMS) devices and split-flow strategy, explore the controllable preparation and monodispersity of chitosan (CS) microspheres, and gain a more comprehensive understanding of microfluidic technology. The experiment has the advantages of easy operation and a short cycle, and it is suitable as an undergraduate experiment.

The Clemmensen reduction is a common example of a reaction demonstrating the deoxygenation of carbonyl groups, which is a topic that has been widely studied in the field of organic chemistry. The use of trimethylchlorosilane, as a substitute for concentrated hydrochloric acid, allows for the reduction of carbonyl groups. The Clemmensen reduction experiment is performed by undergraduates for project-based learning. As a part of this program, students evaluate the influence of active functional groups, electron-donating and electron-withdrawing groups, steric hindrance, and other factors on the modified Clemmensen reduction using different reaction substrates. This lab activity aims to show the effectiveness of teaching organic chemistry laboratory methodologies to undergraduate students and serves as a tool for the final evaluation of practical knowledge using experiments. Project-based learning not only effectively improves the experimental ability of organic chemistry students but also has great importance in the development of interpersonal skills, including teamwork and innovative thinking. This helps to achieve the integration of applied-project-based learning and organic chemistry experimental teaching objectives.

Poinsettia (Euphorbia pulcherrima) contains anthocyanins that dissolve in water and exhibit color changes due to changing pH. This property makes the poinsettia extract a useful acid–base indicator for pH demonstrations. When combined with common household materials, this experiment can be used as an alternative low-cost tool in teaching acid–base chemistry and organic chemistry.

Studies concerning peer-led team learning (PLTL) have shown cognitive and affective benefits to both students and peer leaders, and PLTL has been shown to be effective in diverse environments. However, some studies suggest that not all students may fully engage in group work. Given this need for leaders in STEM and chemistry specifically to create inclusive environments, we conducted a mixed-methods study to explore the impact of leading PLTL sessions on peer leaders’ perceptions of inclusive practices and skills and students’ perceptions of the leader’s inclusion skills. Via surveys, responses were collected from new and experienced (returning) chemistry peer leaders (N = 39) across two time points (fall of 2020 and spring of 2021). Leaders reported moderate to high levels of confidence in most of the 18 inclusion-oriented items. Leader responses from a free-response question on inclusion-skill development (N = 28) were coded into three categories: Collaboration, Environment, and Group-awareness. Data from peer leaders were compared with responses from a PLTL participant feedback survey (N = 206), which corroborated the skills leaders reported cultivating in practice; i.e., (1) students reported observing leaders’ practicing collaboration and environment inclusivity skills and (2) students agreed to strongly agree that leaders created a safe, comfortable environment and encouraged participation from all group members. Overall, our PLTL program cultivates leaders who strive to create inclusive groups, and students largely support this notion; this study adds to the literature on small-group inclusion and peer-leader training.

In 1996, the Chemistry Department at Norwich University converted its two-semester General Chemistry course from a traditional lecture to a Process Oriented Guided Inquiry Learning (POGIL) classroom. The change to POGIL teaching in Norwich General Chemistry classes was brought about by a steady decline in student performance, as demonstrated by final course grades during the mid-1990s. This study statistically analyzed the final grades of 2,481 General Chemistry I and II students from 1982 to 2017. The results of the statistical analysis demonstrate a significant increase in the average GPA across both General Chemistry I and II following the implementation of POGIL at Norwich University. This study indicates that active teaching and learning strategies are successful with Norwich University general chemistry students.