The 50 most-cited articles in Journal of Chemical Education, 2016

Abstract Acid–base chemistry is central to a wide range of reactions. If students are able to understand how and why acid–base reactions occur, it should provide a basis for reasoning about a host of other reactions. Here, we report the development of a method to characterize student reasoning about acid–base reactions based on their description of what happens during the reaction, how it happens, and why it happens. We show that we can reliably place student responses into categories that reflect the model of acid–base reactivity used and whether the students invoke an electrostatic causal argument. However, the quality of student responses is highly dependent on the structure of the task prompt, which must be structured to provide students with enough information for them to understand what is needed. In general, students who construct responses that invoke a causal mechanistic Lewis model are more likely to draw appropriate curved arrow reaction mechanisms.

The Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB) supports scientific research and education worldwide by providing access to annotated information about three-dimensional (3D) structures of macromolecules (e.g., nucleic acids, proteins), and associated small molecules (e.g., drugs, cofactors, inhibitors) in the PDB archive. Researchers, educators, and students use RCSB PDB resources to study the shape and interactions of biological molecules and their implications in molecular biology, medicine, biotechnology, and beyond. RCSB PDB supports development of standards for data deposition, representation, annotation, and validation of atomic structural data obtained from various experimental methods. Uniform representation of PDB data is essential for providing consistent search and analysis capabilities for all PDB users, from beginning students to domain experts. The RCSB PDB Web site provides tools for searching, visualizing, and analyzing PDB data, including easy exploration of chemical interactions that stabilize macromolecules and play…

Peer-led team learning (PLTL) research has expanded from its roots in program evaluation of student success measures in Workshop Chemistry to a spectrum of research questions and qualitative, quantitative, and mixed methods study approaches. In order to develop recommendations for PLTL research and propose best practices for faculty who will integrate PLTL in their classrooms, the theoretical frameworks, study designs, results, and limitations of sixty-seven peer-reviewed studies, spanning a variety of STEM disciplines and institution types, were examined. Five program evaluation themes emerged from this synthesis of the literature: student success measures; student perceptions; reasoning and critical thinking skills; research on peer leaders; and variants of the PLTL model. For each of the themes, areas for future study and implications for practice are suggested to STEM discipline-based education researchers and faculty.

Electrically conducting polymers are one of the promising alternative materials for technological applications in many interdisciplinary areas, including chemistry, material sciences, and engineering. This experiment was designed for providing undergraduate students with a quick and practical approach for preparation of a polyaniline-conducting polymer, demonstrating its application as a conductive coating for fabrication of smart, flexible, conductive textiles. Polyaniline was prepared by chemical oxidative polymerization (COP) of aniline monomer using ammonium persulfate as redox initiator. The polymerization was characterized by color change during the slow induction period, followed by sudden heat release during the polymerization stage due to the autoacceleration nature of this exothermic reaction. This polymerization system was used to demonstrate the heterogeneous precipitation polymerization technique. As a demonstration for the practical application of polyaniline in the area of smart conductive textiles, different nonconductive textile samples were coated with polyaniline…

High Resolution Image Download MS PowerPoint Slide A versatile potentiostat based on inexpensive and “off the shelf” components is reported. The platform was shown to be capable of performing simple electrochemistry experiments, suitable for undergraduate level teaching. The simple design and construction enable easy customization to accommodate a broad array of experimental designs. The equipment was used to calculate the diffusion coefficient of potassium ferricyanide in an aqueous solution, and the obtained result was in good agreement with the literature. Although simple in design, the low cost and good performance of the device make it a competitive alternative for teaching laboratories in the fields of both electronics and electrochemistry, and for developing teaching centers that cannot afford a commercial device.

A very simple protocol for teaching Beer’s Law and absorption spectrophotometry using a smart phone is described. Materials commonly found in high school chemistry laboratories or even around the house may be used. Data collection and analysis is quick and easy. Despite the simple nature of the experiment, excellent results can be achieved.

Organic Chemistry is recognized as a course that presents many difficulties and conceptual challenges for students. To combat the high failure rates and poor student attitudes associated with this challenging course, we implemented a “flipped” model for the first-semester, large-enrollment, Organic Chemistry course. In this flipped course, lectures were replaced by short videos, which were delivered via a course management system, and class time was reserved for problem solving and other active learning activities. We assessed the impact of the flipped course on course grades and failure rate compared to historical course data. The results showed that there was a statistically significant improvement in A and B grades and a decrease in failure/withdrawal rates for the flipped course. We also assessed students’ attitudes toward the course using a valid and reliable instrument, the Attitude toward the Subject of Chemistry Inventory Version 2 (ASCIv2). The results showed a statistically significant increase in students’ emotional satisfaction and intellectual accessibility for the…

The Biochemistry: Biomolecules Structure and Metabolism course’s goal is to promote meaningful learning through an active learning environment. Thus, study periods (SP) and discussion groups (DG) are used as a substitute for lecture classes. The goal of this study was to evaluate how this learning environment influences students’ motivation ( n = 74). Motivation was evaluated by a questionnaire that was described in the literature and by comparing students’ motivation in several courses. The results showed that the students had high achievement and low performance goals in this learning context. This indicates that students worked harder to learn than to get high grades. Students also had high self-efficacy, active learning strategies, and scientific learning values. Moreover, student’s motivation in the active learning environment was higher than or equal to other courses in Pharmacy–Biochemistry. These results demonstrate that the active learning environment had a positive impact on students’ motivation.

Many research and teaching labs rely on USB data acquisition devices to collect voltage signals from instrumentation. However, these devices can be cost-prohibitive (especially when large numbers are needed for teaching labs) and require software to be developed for operation. In this article, we describe the development and use of an open-source USB data acquisition device (with 16-bit acquisition resolution) built using simple electronic components and an Arduino Uno that costs under $50. Additionally, open-source software written in Python is included so that data can be acquired using nearly any PC or Mac computer with a simple USB connection. Use of the device was demonstrated for a sophomore-level analytical experiment using GC and a CE-UV separation on an instrument used for research purposes.

A continuous effort within an undergraduate university setting is to improve students’ learning outcomes and thus improve students’ attitudes about a particular field of study. This is undoubtedly relevant within a chemistry laboratory. This paper reports the results of an effort to introduce a problem-based learning strategy into the analytical chemistry laboratory curricula at North Carolina Central University. This study involved a total of 48 science major students who were taking two analytical chemistry courses, namely Quantitative Chemical Analysis and Instrumental Analysis, spanning Fall 2011 to Spring 2015. Course-based undergraduate research experiences or CUREs have been systematically incorporated into the laboratory components of these two consecutive analytical courses in Fall 2014 and Spring 2015 semesters. Each CUREs project involved identifying a problem, locating an appropriate method via literature search, designing a study, collecting samples, measuring variables, analyzing data, and presenting the results in a formal report and an oral presentation. Our…

An introductory guide to deducing the mechanism of chemical reactions is presented. Following a typical workflow for probing reaction mechanism, the guide introduces a wide range of kinetic and mechanistic tools. In addition to serving as a broad introduction to mechanistic analysis for students and researchers, the guide has also been used by instructors to provide the organizational structure for an upper-level course on organic and inorganic reaction mechanism. After providing students with the tools of mechanistic study, student-led discussions of case studies and an independent proposal project provide preparation for understanding the mechanism of new reactions encountered in independent research.

Characterizing how students construct causal mechanistic explanations for chemical phenomena can provide us with important insights into the ways that students develop understanding of chemistry concepts. Here, we present two qualitative studies of undergraduate general chemistry students’ reasoning about the causes of London dispersion forces in nonpolar species such as helium atoms. In the first study, we used semi-structured interviews to examine students’ verbal explanations for how and why electrical interactions arise between helium atoms. In the second, we used an online short-answer version of the interview task to examine the prevalence of the drawing and explanation types we observed in student interviews. We present a characterization of students’ explanations and drawings in terms of increasing sophistication and demonstrate how it may be used as a model for assessing students’ ability to engage in scientific practices such as explanation.

This project utilizes visual and critical thinking approaches to develop a higher-education synergistic prelab training program for a large second-year undergraduate analytical chemistry class, directing more of the cognitive learning to the prelab phase. This enabled students to engage in more analytical thinking prior to engaging in the analytical action in the laboratory, motivating students to arrive at classes prepared to engage in the material rather than the mechanics (physical processes) of the practical exercises. This reduced the likelihood of cognitive overload at the beginning of the class. Video demonstrations were developed providing both visual demonstrations with audio explanations to reinforce each concept, and students were guided to these through compulsory prelab e-quizzes. The effectiveness of the program was evaluated by academic performance and an attitudinal survey. Attitudes toward the prelab program were very positive, particularly for the e-quizzes. There was no improvement on academic performance in laboratory reports; however, students reported that the…

Building on previous success with a digital pipet badge, an evidence-centered design approach was used to develop new digital badges for measuring the volume of liquids with a buret and making a solution in a volumetric flask. These badges were implemented and assessed in two general chemistry courses. To earn the badges, students created videos of their techniques at the end of lab and uploaded them using the Passport app. Students received individual feedback from their instructors and were able to attempt the technique again if their first performance was unsatisfactory. To evaluate the badge as a laboratory assessment tool, students completed surveys about their knowledge, confidence, and experience using each technique with a retrospective-pre then post survey design. Analysis of these surveys showed statistically significant gains in student knowledge, confidence, and experience across both courses and both badges. Student performance on exams and procedural questions within the badges supports the conclusion that the badges positively impacted student learning of these two…

Chemistry laboratories play an essential role in the education of undergraduate Science, Technology, Engineering, and Mathematics (STEM) and non-STEM students. The extent of student learning in any educational environment depends largely on the effectiveness of the instructors. In chemistry laboratories at large universities, the instructors of record are typically graduate or undergraduate teaching assistants (TAs). Despite the importance of their role in the education of undergraduate students, TAs’ instructional practices have been largely understudied outside specific reform efforts. In this study, we developed a segmented observation protocol, the Laboratory Observation Protocol for Undergraduate STEM (LOPUS), in order to characterize TAs’ instructional styles in a General Chemistry laboratory curriculum. LOPUS captures both students’ and TAs’ behaviors every 2 min as well as initiators of verbal interactions and the nature of these verbal interactions (e.g., data analysis, explanation of concepts). Analyses of 19 videos collected from 15 TAs resulted in the identification of…

Encouraging students to participate in collaborative discourse allows students to constructively engage one another, share ideas, develop joint understanding of the course content, and practice making scientific arguments. Argumentation is an important skill for students to learn, but students need to be given the opportunity in class to engage in argumentation. To investigate the importance of instructor facilitation on argumentation, two iterations of one instructor’s Process Oriented Guided Inquiry Learning (POGIL) physical chemistry course were studied using the Toulmin analysis and the inquiry-oriented discursive moves frameworks. Data were collected by recording class conversations and interactions taking place in the POGIL classrooms. Initial analysis of an individual instructor’s implementation of the POGIL materials provided data regarding the nature of small group and whole class interactions and the nature and quality of student-generated arguments. The instructor was then able to make modifications to the facilitation of that course for the next iteration of the course.…

Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely available, and the cost of 3D printing “inks” is relatively low. Creation of models requires graphing electron orbital probability distributions in spherical coordinates and exporting as stereolithography (.stl) files (a common format for 3D printing). There is both freeware (CalcPlot3D), and license-requiring (Matlab, Mathematica, Maple) software capable of plotting orbital equations and exporting in the required format. The process of creating the orbitals is relatively simple, and the 3D printing methodology is cost-effective.

Advances in software and hardware have promoted the use of computational chemistry in all branches of chemical research to probe important chemical concepts and to support experimentation. Consequently, it has become imperative that students in the modern undergraduate curriculum become adept at performing simple calculations using computational software, interpreting computational data, and applying computational data to explain chemical phenomena. We utilize computational chemistry in a high-enrollment (>1200 students/year), undergraduate organic chemistry laboratory course in a manner similar to that of organic chemistry researchers. We have employed WebMO as a web-based, easy-to-use, and free front-end interface for Gaussian09 that allows our students to complete ab initio and density functional theory (DFT) calculations throughout the curriculum. Rather than an isolated exposure to computational chemistry, our students use computational chemistry to obtain a deeper understanding of their experimental work throughout the entire semester. By integrating calculations into the…

This study describes the development and application of a three-tier test as a valid and reliable tool in diagnosing students’ misconceptions regarding some basic concepts about carbohydrates. The test was administrated to students of the Pharmacy Department at the University of Bijeljina (Serb Republic). The results denoted construct and content validity of the instrument and its high reliability. Considering the results entirely, it was determined that the presence of a third tier in a task significantly affected the number of identified misconceptions and the assessment of scientific knowledge. These findings suggest that certain incorrect responses should be attributed to the lack of knowledge rather than to misconceptions, and likewise, some correct responses should be attributed to the lucky guess rather than to scientific knowledge, which implies a higher credibility of the results obtained. In this study, several misconceptions about carbohydrates were revealed. As there are only a few studies examining students’ misconceptions in chemistry using three-tier tests available…

Nuclear magnetic resonance spectroscopy (NMR) plays a key role in introductory organic chemistry, spanning theory, concepts, and experimentation. Therefore, it is imperative that the instruction methods for NMR are both efficient and effective. By utilizing eye tracking equipment, the researchers were able to monitor how second-semester organic chemistry students solved NMR items. Graduate and advanced undergraduate students were used as a comparison group. The students in the course were characterized as novices, while the comparison group served as “experts” in statistical comparisons of problem-solving strategies. This study examines aspects of proton NMR spectra that each group considered while matching organic structure with a provided spectrum. Significant differences between the expert and novice groups as well as within the novice group were observed. The participants’ search patterns (i.e., gaze frequency and gaze order) were interpreted in terms of a problem-solving approach. These results can provide subtle information about the learner’s attention and cognition.

A lab appropriate to introduce voltammetric techniques and basic electrochemical parameters is described in this work. It is suitable to study theoretical concepts of electrochemistry in an applied way for analytical undergraduate courses. Two electroactive species, hexaammineruthenium and dopamine, are used as simple redox systems. Screen-printed electrodes are used in order to allow the students to focus on the electrochemistry and avoid tedious instrumentation preparation. The analytical determination of the species studied with sensitive techniques such as differential-pulse or square-wave voltammetry is also performed.

Hydrogen bonds are very important chemical structures that are responsible for many unique and important properties of solvents, such as the solvation power of water. These distinctive features are directly related to the stabilization energy conferred by hydrogen bonds to the solvent. Thus, the characterization of hydrogen bond energetics has been vital for many areas of science. We present a laboratory experiment for physical chemistry in which the hydrogen bond energetics between methyl acetate and water is investigated by Fourier transform infrared spectroscopy (FTIR). The experiment consists of measuring the temperature dependent IR spectra of methyl acetate to determine the changes in the enthalpy and entropy of making/breaking hydrogen bonds. This experiment aims at providing the students with hands-on experience in the following topics: solution and sample cell preparation, IR spectra collection and analysis, and data modeling and thermodynamic calculations. The overall objective of this experiment is to familiarize chemistry students with a methodology used to extract…

Organic chemistry is very challenging to many students pursuing science careers. Flipping the classroom presents an opportunity to significantly improve student success by increasing active learning, which research shows is highly beneficial to student learning. However, flipping an entire course may seem too daunting or an instructor may simply choose to use this approach selectively. This exploratory, mixed-methods study examines the effectiveness of a partially flipped course in the first semester organic chemistry course. Two sections were taught by the author in Fall 2015: a control section ( n = 28 students) using a lecture-based format, and a flipped section ( n = 26 students), where 8, 75 min classes (a third of the course) were taught with flipped pedagogy. Significant improvements in test questions on flipped topics were observed, as well as a significant reduction in the course withdrawal rate. While the average overall course grade was similar in the two sections, the flipped section had 25% more A’s and B’s. Survey and focus group data show that by the end of the…

High Resolution Image Download MS PowerPoint Slide The hallmark of game-based learning is that students discover concepts through trial and error as they play. With the digital landscape in higher education shifting to mobile-first, new tools for learning chemistry are both possible and needed. Interactive games for chemistry bring intuitive content directly to students through their devices. The game Chairs! was created to teach the ring flip of cyclohexane. The development of this new mobile learning tool for organic chemistry and its implementation in classrooms are described.

Mastering the many different diagrammatic representations of molecules used in organic chemistry is challenging for students. This article summarizes recent research showing that manipulating 3-D molecular models can facilitate the understanding and use of these representations. Results indicate that students are more successful in translating between diagrams when they have models available, that using a model to enact the translation process in the world is predictive of learning, and that using models as feedback (to check the accuracy of diagram translation) is particularly effective. Model-based feedback is superior to verbal feedback alone, models scaffold learning rather than act as a crutch, learning with model-based instruction is resilient over a delay of several days, and learning with models transfers to performance when models are no longer available. Finally, virtual models are equivalent to hand-held models in promoting learning in the studied contexts.

Teaching materials characterization to support student research projects requires a systematic educational approach, because characterization involves a combination of analysis instruments. As analytical instruments are expensive, it is difficult to provide multiple sets simultaneously. An effective educational program allows students to select their own research materials to characterize and apply their personal strategies of instrumental analysis. These strategies are designed around the purposes of the analytical instruments, e.g., molecular structure analysis, crystal structure analysis, morphology assessment, surface analysis, elemental analysis, and thermal analysis. An open-ended laboratory complements this educational purpose. Here, we report on an open-ended laboratory program for fourth-year undergraduate and graduate students at the Materials Characterization Central Laboratory at Waseda University (Tokyo, Japan). The goals of our open-ended laboratory program are to enable students to (1) conduct instrumental analysis, (2) operate analytical instruments, and (3)…

In this paper, the characteristics and results of a teaching unit based on the use of educational games to learn the idea of chemical elements and their periodic classification in secondary education are analyzed. The method is aimed at Spanish students aged 15–16 and consists of 24 1-h sessions. The results obtained on implementing the teaching unit are assessed with a focus on the development of students’ understanding of the topics covered and their perceptions toward the role of games in the learning process. The data collection methods used included a learning assessment test (administered before the unit was started and one month after completion of the unit) and a questionnaire to assess the students’ learning experience. As a complementary method to acquire data, the teacher keeps a diary. The main conclusion was that students progressed significantly in the areas of learning related to knowledge of the Periodic Table and its nature and history, but a lower level of progress was found in the application of knowledge and the use of evidence to draw conclusions. Furthermore,…

High Resolution Image Download MS PowerPoint Slide A user-friendly set of computer-aided design (CAD) models and stereolithography (STL) files is reported for the production of simple and inexpensive 3D printed colorimeters. The designs shared here allow educators to provide active learners with tools for constructing instruments in activities aimed at exploring the technology and fundamental principles related to quantitative analysis. While previous efforts focused on fabricating inexpensive instruments from building blocks and other household items, 3D printing transcends the limitations of conventional tooling. The digital models described here are flexible in design, printed quickly, and each requires less than a dollar’s worth of plastic filament. These designs are compatible with simple CAD software, such as Inventor Professional and Tinkercad, commonly available to educators and students. With the use of programs of this type, CAD files are easily modified in order to produce customized models for exploring a variety of concepts inaccessible to more conventional instruments.…

Development of benchtop, portable Fourier transform nuclear magnetic resonance (NMR) and infrared (IR) spectrometers has opened up opportunities for creating university–high school partnerships that provide high school students with hands-on experience with NMR and IR instruments. With recent changes to the international baccalaureate chemistry and advanced placement chemistry curricula, NMR and IR spectroscopy can be mapped directly to content that is already built into general, organic, and materials courses offered at the high school level. We developed a program in which the university provides professional development opportunities to high school chemistry teachers and further opportunities for these teachers to bring benchtop NMR and IR instruments directly into their own classrooms. This partnership not only benefits students by providing unique active learning experiences, but also offers opportunities for high school teachers’ professional development through on-campus training workshops. These partnerships may also expand university outreach efforts in local secondary…

The sheer number of reactions covered in an undergraduate organic chemistry course can be overwhelming. Students are expected to demonstrate a thorough knowledge of these reactions in order to understand the logic of organic synthesis. A method that allows students to systematically solve organic synthesis problems without memorizing dozens of reactions would be beneficial. Two new card games, Synthesis and Synthetic Dominos, have been developed using a variation of traditional flash cards. Both of these games allow players to develop the logical skills needed to solve organic synthesis problems, review organic functional groups, and review reaction reagents. The first game, Synthesis, is a solitaire game that uses reaction cards to link up a starting material and target by connecting functional group conversions. The game play mimics the process used to solve synthesis problems. The second game, Synthetic Dominos, is a single-player or multiplayer game that has a gameplay similar to that of Dominos. An initial functional group card is dealt, and then players play their cards to…

Electrochemical analysis is an important skill to teach in chemistry curricula because it is a critical tool in current high-impact chemical research. Electrochemistry enables researchers to analyze a variety of systems extending from molecules to materials that encompass research themes ranging from clean energy to substrate activation in biological systems. Specifically, it can reveal information about catalytic efficiency, the role of catalysts, and the nature of chemical reduction and oxidation (redox) processes. Researchers working in the area of catalysis rely heavily on electrochemistry, using it to identify effective catalysts and optimize reaction conditions. This laboratory experiment begins with an introductory tutorial to electrochemistry by guiding students through the use of several electrochemical techniques using the ferricyanide/ferrocyanide redox couple as a model system. The techniques covered in the tutorial include cyclic voltammetry, differential pulse voltammetry, Tafel analysis, and bulk electrolysis. The protocol then applies these techniques to…

Abstract Interlocking toy building blocks (e.g., Lego) as chemistry learning modules for blind and visually impaired (BVI) students in high school and undergraduate introductory or general chemistry courses are presented. Building blocks were assembled on a baseplate to depict the relative changes in the periodic properties of elements. Modules depicting the electron configuration of an element and molecular orbital theory were also constructed. Modules were presented as a hands-on learning experience for a group of BVI students followed by a survey. Modules were also presented as classroom demonstration for an undergraduate general chemistry class of sighted students.

In this laboratory experiment, upper-division undergraduate chemistry and biochemistry majors investigate amide-bond-forming reactions from a green chemistry perspective. Using hydrocinnamic acid and benzylamine as reactants, students perform three types of amide-forming reactions: an acid chloride derivative route; a coupling reagent promoted method; and a boric acid catalyzed condensation. After isolation of the common product, students assess the reactions using the 12 Principles of Green Chemistry and several green chemistry metrics: atom economy; reaction mass efficiency; process mass intensity; and the EcoScale. In addition to assessing what route is the greenest, students also compare the metrics to discern what aspects of green chemistry each metric captures. In order to extend sustainability to economic considerations, the projected “front-end” cost of synthesizing a kilogram of the amide is calculated based on data from each reaction. The experimental work is conducted over two 3 h laboratory periods.

Quantification of the many constituents that make up our food, whether they are desirable (vitamins, antioxidants, nutrients) or undesirable (pesticides, toxins), is one of the most practical applications of chemistry. In this study, kombucha, a popular fermented tea beverage, was analyzed using acid–base titration and high-performance liquid chromatography (HPLC). Kombucha is made via the fermentation of sweetened black tea with a symbiotic culture of bacteria and yeast (SCOBY), which produces acetic acid in addition to a variety of other organic acids and vitamins. The aim of this study was to analyze the acid content of kombucha over a 21-day fermentation period in order to characterize the fermentation kinetics. Titrimetric analysis revealed that the total acidity increased linearly with fermentation time at a rate of 1.5 mM/day. The acetic acid content was also quantified by HPLC at 7-day intervals by standard addition and compared to the total acidity determined by titration. A paired Student’s t test was used to validate the methods. In an extension of the lab, HPLC was also…

The research-based pedagogical strategy of flipped classes has been shown to be effective for increasing student achievement and retention in postsecondary chemistry classes. The purpose of flipped classes is to move content delivery (e.g., lecture) outside of the classroom, freeing more face-to-face time for active learning strategies. The opportunity to engage in active learning with students can be a challenge for instructors of large classes (more than 100 students). Furthermore, there has been little discussion in the chemical education literature to provide instructors with detailed descriptions of successful implementations of flipped classes combined with active learning in large classes. To this end, this report provides a comprehensive description and evaluation of a coordinated implementation of flipped classes with peer-led team learning (PLTL) for second-semester general chemistry with class sizes greater than 200 students. This approach is described as “Flipped PLTL”. This report includes details about creation of videos for flipped instruction, class structure, and…

High Resolution Image Download MS PowerPoint Slide This commentary discusses how the principles of universal design for learning (UDL) can be applied in the science laboratory with an emphasis on assisting students who experience stress in the laboratory environment. The UDL approach in the laboratory is based on three elements: open-mindedness, supportive communication, and analysis and adaptation of laboratory curriculum. “Supportive communication”, a novel element of our approach comprising interaction methods adapted from counseling therapy, is introduced. A brief discussion of a workshop for chemistry faculty and graduate students on the UDL approach is presented.

In this undergraduate analytical chemistry experiment, students quantitatively assess the antibacterial activity of essential oils found in thyme leaves ( Thymus vulgaris ) in an authentic, research-like environment. This multiweek experiment aims to instill green chemistry principles as intrinsic to chemical problem solving. Students progress through various techniques including extraction, chromatography (TLC and HPLC), culturing bacteria, and disk diffusion via a process of guided exploration that emphasizes green experimental design. Approximately 600 undergraduate students carried out the experiment and self-reported substantial learning gains.

A course is described where students are engaged in an inquiry-based quarter-long research project to synthesize a known pharmaceutical target. Students use literature search engines, such as Reaxys and SciFinder, and the primary chemical literature as resources to plan and perform the synthesis of their pharmaceutical target. Through this process, students develop critical thinking, problem solving, and data analysis skills in the laboratory setting. Teaching assistants guide students through three phases of the research process: (1) literature-based proposal, (2) experimentation and analysis, and (3) communication of research findings by oral presentation and written report. This course is designed for upper-division chemistry majors, taken as the third-quarter organic laboratory class after two quarters of introductory laboratory courses and two quarters of the associated organic chemistry lecture courses. Nine different teaching assistants have taught the course described to over 90 students in four different quarters.

Some observations about the advantages and potential practical challenges of the “flipped classroom” approach in a general chemistry course are presented.

Molecular model kits have been used in chemistry classrooms for decades but have seen very little recent innovation. Using 3D printing, three sets of physical models were created for a first semester, introductory chemistry course. Students manipulated these interactive models during class activities as a supplement to existing teaching tools for learning typically difficult concepts that currently lack physical models: the Bohr model of the atom, bond polarity, and hybridization. The results from student surveys show that these easy-to-produce models have a positive impact on students’ perceptions of learning.

A laboratory project for the upper-division physical chemistry laboratory is described, and it combines IR and Raman spectroscopies with Gaussian electronic structure calculations to determine the structure of the oxalate anion in solid alkali oxalates and in aqueous solution. The oxalate anion has two limiting structures whose vibrational spectra have distinct differences: planar with D 2h symmetry and nonplanar with D 2d symmetry. In the former case, the IR and Raman spectra are complementary. Students measure the IR and Raman spectra of solid Na 2 C 2 O 4, K 2 C 2 O 4, and Cs 2 C 2 O 4, and a nearly saturated aqueous solution of K 2 C 2 O 4 . They also carry out Gaussian calculations on the oxalate anion to predict the vibrational wavenumbers of both the planar and nonplanar structures and use the results to assign the spectra. By considering their results for the four samples, they decide on the oxalate structure in each and defend their choice in a report. The complexity of the project immerses the students in vibrational spectroscopy so that they learn the subject at a deeper…

Various cognitive aids (such as change of color, arrows, etc.) are provided in virtual environments to assist users in task realization. These aids increase users’ performance but lead to reduced learning because there is less cognitive load on the users. In this paper we present a new concept of procedural guidance in which textual information regarding the procedure of a task is provided to users. The users convert this information into physical actions to complete the task, which enhances their learning by creating a consolidated mental model. We use Multimodal Virtual Chemistry Laboratory, where students simulate a chemistry experiment with the help of procedural guidance. Evaluations reveal that the proposed guidance enhances students’ learning and consequently increases their performance in real-world situations.

In this work we describe an authentic performance project for Instrumental Analysis in which students designed, built, and tested spectrophotometers made from simple components. The project addressed basic course content such as instrument design principles, UV–vis spectroscopy, and spectroscopic instrument components as well as skills such as evidence-based decision-making, seeking and applying knowledge, teamwork, and breaking down complex problems. Over the course of the seven-week project, students produced unique, functional spectrophotometers with creative designs. Students reported a high level of engagement and learning during the project. Student performance on a UV–vis spectroscopy assessment instrument improved significantly (28%) from a pretest to a post-test, with the greatest gains occurring in items aligned to the project learning outcomes.

It is not uncommon for students to view laboratory instruments as black boxes. Unfortunately, this can often result in poor experimental results and interpretation. To tackle this issue, a laboratory course was designed to enable students not only to critically think about operating principles of the instrument but also to improve interpretation skills. Students were required to build their own visible spectrometer using interlocking building bricks with simple optical elements and a Raspberry Pi computer. Experiments were then conducted to explore the instrumental capabilities while, at the same time, using Python programming to plot data, perform linear least-squares fitting, and calculate errors. Instrument response and spectral measurements were followed by kinetic studies, enabling the students to tackle a “real” problem by extracting rate constants. The main learning outcomes were that the students would gain a better understanding of instrumental components and at the same time learn valuable analytical techniques such as calibration, determination of the limits of linearity,…

This article describes how to construct a simple, inexpensive, and flexible UV-photometer using one LED (355 nm) as the light source and another (355 nm) as the detector, one resistor, some wiring, a few Lego bricks, and a millivolt meter. The photometer is used to explore several aspects of molecular absorption spectrometry. As practical applications, the amounts of folic acid in folic acid tablets and cinnamaldehyde in cinnamon were found. The results were in accordance with those obtained using a commercial spectrophotometer.

We report an intensive graduate teaching assistant (GTA) training program developed at The University of Chicago. The program has been assessed and has been successful in preparing GTAs for effective discussion and laboratory teaching for both general and organic chemistry. We believe that this training program can provide insightful information to benefit other similar GTA training programs in the future.

A programmable dual-syringe pump was constructed from inexpensive materials. The syringe pump can accommodate two syringes of the same or different size without any modification of the platform. Unlike other reported open-source syringe pumps, the syringes can be dispensed independently of one another without modification. The total cost of the syringe pump is roughly $100 including the microcontroller and roughly $60 without.

High Resolution Image Download MS PowerPoint Slide In this work, a versatile and user-friendly selection of stereolithography (STL) files and computer-aided design (CAD) models are shared to assist educators and students in the production of simple and inexpensive 3D printed filter fluorometer instruments. These devices are effective resources for supporting active learners in the exploration of instrument design and performance. In contrast to sophisticated commercial-grade fluorometers, the models provided here are open source, customizable for a variety of applications, and easily assembled by students in activities that directly confront the “black box” perception of analytical instrumentation. In order to aid beginner CAD and 3D printer users, these models are compatible with accessible software packages, such as 123D Design and Inventor Professional. Additionally, CAD tutorials and extensive slicer settings are supplied to assist educators and students in modifying digital designs and obtaining reliable 3D prints. The provided filter fluorometer models are printed quickly,…

The use of hand-held 3D printing technology provides a unique and engaging approach to learning VSEPR theory by enabling students to draw three-dimensional depictions of different molecular geometries, giving them an appreciation of the shapes of the building blocks of complex molecular structures. Students are provided with 3D printing pens and two-dimensional templates which allows them to construct three-dimensional ABS models of the basic VSEPR shapes. We found that the learning curve associated with manipulating the pen accurately and the time required to draw a structure is sufficiently high that this exercise would need to be limited in a laboratory setting to students each being tasked with drawing a different molecule; however, in the correct setting, hand-held 3D printing pens are a potentially powerful tool for the teaching of VSEPR theory.

In this work, a laboratory experiment to introduce graduate students to nanotechnology is described. Students prepared poly(lactic- co -glycolic acid) (PLGA) nanoparticles using two different synthesis procedures, a single and a double emulsion–solvent evaporation method. The students also performed a physicochemical characterization of the prepared nanoparticles (NPs) by determining the hydrodynamic size and zeta potential values through Dynamic and Electrophoretic Light Scattering, respectively. The experiments were designed to be accomplished in two 180 min sessions and have been successfully conducted by 24 graduate students.