教学课程资源库 更多>>

关键词： “互联网+”   有机化学教学   核心素养  

摘要： “互联网+”时代,教育教学信息化改革持续加速,新型多媒体教学模式不断发展,教育教学软件不断更新,产生了大数据分析辅助教育的特征。有机化学教学中,信息技术在学生的核心素养培养中起到了越来越重要的作用。

关键词： Salts   Hydrocarbons   Aromatic compounds   Sulfones   Irradiation  

摘要： The number of research papers that report photo-catalyst-free protocols is currently increasing. Among the different approaches proposed, the conversion of a strong C-X bond of a stable substrate into a photolabile reactive moiety has been recently proposed. In this Synopsis, we introduce the so-dubbed dyedauxiliary group strategy by focusing on arylazo sulfones that are bench stable and visible-light responsive derivatives of anilines that have been exploited as precursors of a wide range of intermediates, including carbon-centered radicals as well as aryl cations.

关键词： Organic Chemistry   Hands-On Learning/Manipulatives   Problem Solving/Decision Making   Aqueous Solution Chemistry   Synthesis   Thin Layer Chromatography  

摘要： We present an experiment designed to hone the decision-making skills of (undergraduate) chemistry students by using aqueous crossed aldol reactions. Here, we present two simple crossed aldol reactions based on inexpensive and readily available materials: The condensation of vanillin and cinnamaldehyde with acetone. The procedure uses the variation of reaction conditions (including the use of inexpensive chlorides, namely LiCl or NiCl2, as catalysts and variation between different mild reaction temperatures), as well as different simple preparative and analytical techniques such as filtration, recrystallization, melting point measurements, thin-layer chromatography and IR spectroscopy aiming for the students to find the optimal reaction conditions, thus honing their decision-making and time management skills. Furthermore, those experiments are designed for a laboratory session of 3 to 4 h.

关键词： General Public   First-Year Undergraduate/General   Second-Year Undergraduate   Interdisciplinary/Multidisciplinary   Communication/Writing   Student-Centered Learning  

摘要： A two-year targeted intervention designed to improve students' oral communication skills in an organic chemistry laboratory course is described. The study compares the oral communication skills of groups who received interventions versus those who did not. The collaborative effort involving chemistry and English faculty and an instruction librarian assessed student performance on several measures of oral communication competency. Participants blindly placed themselves in either treatment or control groups. Both groups received identical basic instruction on poster layout and design. The treatment group received additional instruction on multiple aspects of oral communication and presentation skills. A comparison of the outcomes of the two groups found that those receiving the additional targeted interventions performed better on measures such as the ability to describe clearly the research project and fluency with scientific terminology.

关键词： Second-Year Undergraduate   Interdisciplinary/Multidisciplinary   Laboratory Instruction   Organic Chemistry   Hands-On Learning/Manipulatives   Green Chemistry   Reactions   Plant Chemistry   Microscale Lab  

摘要： We report a series of experiments based upon cinnamon oil that were developed to provide a practical integration of green and sustainable chemistry concepts for the organic chemistry laboratory. Five experiments centering around cinnamaldehyde as a green, plant-based chemical were performed by undergraduate students in a second-year organic chemistry class. Cinnamon oil was obtained through hydro-distillation, and cinnamaldehyde was used to demonstrate the use of a secondary metabolite in chemistry laboratories. Subsequently, a reduction reaction, aldol reaction, and Schiff base formation were carried out. Through these experiments, students are able to practice techniques such as thin-layer chromatography, column chromatography, recrystallization, and measurement of melting points along with UV, FTIR, and H-1 NMR spectroscopy. Microscale practices were employed in each of the reactions, and microscale column chromatography was used for purifications. The final experiment was an antimicrobial activity assessment of cinnamon oil and the cinnamaldehyde derivatives obtained from the previous experiments. Along with an interdisciplinary component, students were exposed to sunscreen chemistry and were led to consider the many uses of each product obtained. These experiments were based upon a single, inexpensive plant metabolite and biobased material to educate students about green chemistry and its practical applications in the undergraduate laboratory.

关键词： Upper-Division Undergraduate   Organic Chemistry   Problem Solving/Decision Making   Acids/Bases   Mechanisms of Reactions   Nucleophilic Substitution  

摘要： In organic chemistry, meaningful learning is essential when reflecting about multiple reaction pathways and selecting reaction centers-topics that require a complex and multivariate reasoning approach to problem-solving. Meaningful learning is characterized by abstract, analytical thinking that might be time-consuming, whereas rote learning, on the other side of the continuum, facilitates simple heuristic-based recall of information. To challenge organic chemistry students to shift their problem-solving approach from rote learning to meaningful learning, we designed task sequences that initially required students to use heuristics followed by an enforced reflection about alternative reaction pathways. Twenty-nine students who were enrolled in a third-year organic chemistry course participated in the study. They solved two tasks, each with four subtasks, which sequentially provoked the use of different problem-solving approaches. The tasks are centered on the chemical concept of nucleophilicity and electrophilicity. In the first step, students were prompted to predict the product of an easy and familiar reaction. This step aimed at provoking the use of heuristics. Afterward, students received five alternative product cards and were prompted to reflect on the plausibility and the alternative mechanistic pathways leading to these products. Evaluation of these task sequences revealed (a) to what extent students were engaged in reflecting on their own problem-solving approaches and (b) the aspects students perceived as important for adopting a more meaningful approach to solving typical tasks in organic chemistry. Implications and limitations of the designed tasks are discussed.

关键词： Second-Year Undergraduate   Organic Chemistry   Laboratory Instruction   Inquiry-Based/Discovery Learning   Problem Solving/Decision Making  

摘要： Research experiences are widely understood to be valuable for the intellectual and professional development of undergraduate science students. Course-based undergraduate research experiences (CUREs) have become popular as a means of engaging large numbers of students in research by leveraging institutional supports for laboratory courses. At Willamette University, we have adapted a guided-inquiry experiment that gave unexpected results into a CURE in the lower-division organic chemistry curriculum. This experience has engaged several cohorts of students in a 7 week investigation focused on identifying the mechanistic origin of a nonstereospecific hydroxybromination of Z-stilbene, an observation that contradicts how this addition reaction is presented in standard organic chemistry curricula. Each year, the cohort experimentally "discovers" the anomalous stereochemical outcome of the addition reaction. Students then participate in a workshop focused on developing mechanistic hypotheses that can account for the result and on designing experiments that will address their hypotheses. Over the next three lab sessions, students execute their experiments, reconsidering and revising their hypotheses as their data dictate. The experience culminates in formal oral and written presentations of results. Student perceptions of the pedagogical value of the CURE, the effect of the lab on their self-efficacy, and the novelty of research being conducted were assessed in multiple class cohorts, while faculty perceptions of changes in student behavior and skill were also documented.

关键词： Organic Chemistry   Computer-Based Learning   Synthesis   General Public   Mechanisms of Reactions  

摘要： Organic reaction mechanisms are one of the most challenging question types in introductory organic chemistry subjects. We identified that the students within our health-based programs had traditionally performed poorly with these question types. With the aim to increase student engagement, we have developed a series of lightboard videos demonstrating key organic mechanisms. The effectiveness of these lightboard videos was first evaluated in a postlecture group learning session, and second as an extra resource over a four year period by comparing the exam results. The student overall showed an increase in performance in the subject, and a deeper engagement over the time during which we analyzed the effectiveness of these resources.

关键词： Second-Year Undergraduate   Organic Chemistry   Analogies/Transfer   Problem Solving/Decision Making Mechanisms of Reactions   Nucleophilic Substitution   Chemical Education Research  

摘要： Reaction mechanisms commonly used in organic chemistry are a great challenge for students in terms of understanding the representation and inferring the appropriate chemical concepts. In order to support the process of identifying and selecting chemical concepts, purposefully designed case comparisons are widely used. While these tasks place great demands on students' problem-solving capabilities, it is unknown how learners distribute their attention on the complex and information-rich representations. Understanding students' visual decoding behavior when dealing with case comparisons could provide valuable insights into supporting students' problem-solving process. In this exploratory study, we employed eye-tracking methodology to observe beginner and advanced undergraduate chemistry students when working through case-comparison tasks. By establishing a novel eye-tracking measure, the fixation/transition ratio, distinct viewing behaviors could be observed. Results indicate significant differences between both status groups. Advanced students are overall faster in their decision-making and transition more frequently between the representations, indicating a higher selectivity for chemically relevant entities. Further, the results show a significant impact of the visual complexity of a representation on students' visual behavior. Implications for designing case comparisons and supporting students' decoding process are discussed.