Journal of Chemical Education最新文献

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.

In undergraduate science education, laboratory courses stand as essential cornerstones of experiential learning. Chemistry laboratory courses offer students unique hands-on experiences that bridge the gap between theoretical knowledge and practical application. The journey through the undergraduate chemistry curriculum is paved with a series of conceptual gateways known as threshold concepts that can dramatically shape a student's understanding and success. We identified the idea of intermolecular forces (IMFs) as a threshold concept to students' ability to link molecular structures, properties, and applications to real-world problems such as extraction and separation of compounds. The development of course-specific pedagogical tools can provide students with the scaffolding necessary for the transition from novice to expert-level disciplinary comprehension. This work presents the development process of a Threshold Concept Assessment Rubric (TCAR) based on Johnstone's triangle framework and discusses its application for evaluating students' progress in overcoming a threshold concept. The rubric is used in a 200-level multilayer laboratory course that is intentionally designed with intermolecular forces as the central theme. We analyze the role and structure of different questions to provide a holistic assessment of students' learning processes using sample assignments. Furthermore, we demonstrate how insights from statistical analyses can highlight areas in which students struggle to gain expert or exemplary-level understanding of IMFs. This rubric development approach can be applied to other threshold concepts.

Faculty development programs play a crucial role in enhancing learning by equipping educators with the necessary skills, knowledge, and pedagogical strategies to teach more effectively. One such program is the Promoting Active Learning in Analytical Chemistry (PALAC) workshop, which aimed to educate faculty on methods to create and use active learning course materials to support students during the process of learning. This research aimed to assess the design of classroom instructional materials generated by faculty that attended the PALAC workshops. The theories of Vygotsky's zone of proximal development and scaffolding were used as lenses to characterize the materials because they describe the benefits of providing support through the process of developing knowledge. The active learning materials were analyzed by assigning the cognitive levels of processing, as described by Marzano's taxonomy, to all questions asked across 134 in-class activities. The use of the cognitive levels of processing allowed the researchers to gauge the presence of scaffolding by tracking how the cognitive levels of processing changed from question to question across each in-class activity. The results from this study indicate that the majority of materials provide opportunities for students to engage with higher-order questions, but there is less evidence for the effective and consistent structuring of the materials. These results have implications for future faculty development programs, suggesting the need to allot more time for faculty to practice developing effective classroom materials. In conjunction, this work demonstrates the effective use of Marzano's taxonomy in assessing the cognitive structure of in-class activities.

Specifications Grading was implemented in a multisection upper-level analytical chemistry laboratory, the first reported for a full lab course redesign in the discipline or in an upper-level chemistry lab class. The primary goals of the redesign were (1) to assess student proficiency of three separate goals: techniques, data quality, and written communication, with three separate assignments, (2) to encourage growth across the semester, providing students the opportunity to show their improvement, and (3) to implement a clear grading system that emphasized equity across the multisection course. Mark distributions on assignments show an increase in students earning exemplary marks on first attempts as the semester progressed, indicating improvement not only within assignments but also across assignments. Student feedback surveys indicate high satisfaction with the grading scheme, with over 72% of survey respondents indicating they would like the grading scheme applied to other courses. Additionally, survey results demonstrate success in achieving the three goals, with students able to articulate the benefits associated with the priorities of the course structure. A particular focus was on the actionability and timeliness of instructor feedback, a hallmark of specifications grading, which students also highly rated. Teaching Assistant feedback indicated that, despite more time spent on grading, teaching satisfaction was higher compared to other courses. The use of regular student feedback to improve the course design is also discussed.