Chemistry Laboratory Curriculum Research Articles

Spectroscopic Monitoring and Modeling Drug Dissolution for Undergraduate Chemistry Curriculum.

The pharmaceutical and medicine manufacturing industry has become the largest industrial sector for the employment of chemists, indicating a need for experiments with a pharmaceutical sciences context in the undergraduate chemistry curriculum. In the pharmaceutical industry, testing drug dissolution is a key analytical task for solid oral dosage forms that is performed in different phases of drug development to test the release behavior of new formulations, ensure consistency between manufacturing lots, and help predict the in vivo absorption of the drug substance after administration. However, there are a limited number of laboratory experiments in dissolution testing developed for the undergraduate chemistry curriculum. To help students obtain hands-on experience in dissolution testing, a protocol has been developed for an undergraduate chemistry laboratory course for students to build a dissolution apparatus, monitor dissolution processes, model the dissolution to extract kinetic parameters, and evaluate the consistency between dissolution curves with FDA regulated methods. Students successfully collected dissolution curves and completed the modeling analysis with nonlinear least-squares fitting. The designed dissolution protocol has been evaluated to have consistency and reproducibility to be implemented in the undergraduate chemistry laboratory curriculum.

Development of an Infographic Assignment for an Introductory Chemistry Laboratory Curriculum

In recent years, pedagogical advancements have allowed the adoption of more engaging forms of course assignments to help students better understand and communicate chemistry. In this context, informational graphics, known as infographics, emerge as an effective teaching aid in educational settings and in disseminating scientific content to the public. This article describes the design of an infographic assignment and its implementation in a first-year chemistry laboratory course at the University of British Columbia’s Okanagan campus. The overarching goal of this assignment was to incorporate the thematic framework of the United Nations Sustainable Development Goals into the laboratory curriculum while encouraging systems thinking and promoting science communication initiatives. The students’ attitudes toward this assignment via submitted self-reflection survey results are also discussed. Our findings reveal an overall positive student experience suggesting the infographic assignments’ ability to foster student engagement and critical thinking skills.

A structural model of student experiences in a career‐forward chemistry laboratory curriculum

AbstractPersistence is a major issue facing students, particularly those who are both female and from underrepresented ethnic minorities (URM). A closer look at the variables affecting their commitment and capacity for continuing the pursuit of their goal allows us to better design support systems that bolster persistence. This study tests a structural equation model (SEM) for students using a career‐forward laboratory chemistry curriculum based upon the Mediation Model of Research Experience (MMRE) that explains the relationships among self‐efficacy, identity as an engineer, and commitment to an engineering career. Data were collected from 426 undergraduate engineering majors at the end of the semester using a previously constructed survey for three semesters of general chemistry laboratory for engineering majors. The research question was addressed using bivariate correlations and a series of SEMs where multigroup analyses were conducted separately for non‐URM and URM participants. Bivariate correlations show significant positive associations between all four variables for the entire group of students. However, when disaggregated, the only significant association for URM participants (n = 109) was between identity as an engineer and commitment to an engineering career. Notably, teamwork self‐efficacy was a negative predictor of commitment to an engineering career for URM participants. Beta‐coefficients from the SEM show that identity and engineering self‐efficacy are the variables most predictive of commitment, with identity being nearly twice as predictive for URM students. This study adds support for professional identity as a key predictive variable for career commitment for URM participants and indicates that a laboratory curriculum that emphasizes applied professional practice can support persistence. Considering the degree to which teamwork is emphasized generally, additional studies are needed to better understand the implications for URM students. Particularly in applications that emphasize long‐term outcomes.

Teaching Single Crystal X-ray Crystallography in the Undergraduate Classroom with Sugar and Epsom Salt

We developed a single crystal X-ray crystallography experiment based on the crystal structure of sucrose (table sugar), and a more challenging experiment using Epsom salt. Both crystals are readily available in X-ray quality crystalline form. In these experiments, students mounted a crystal on a MiTeGen loop and analyzed it using a Rigaku XtaLAB Mini diffractometer (built 2011). Students generated models of both compounds using CrysAlisPro, Olex2, SHELXT, and SHELXL. All aspects of this experiment use free software programs which have user-friendly interfaces. A step-by-step laboratory protocol for determining the structure of both compounds is included in the Supporting Information. These experiments were used in the Fall of 2019 at the Junior and the Senior level. In the Summer of 2020, a take-home version of the lab was created in response to the Novel 2019 Coronavirus (COVID-19) pandemic and implemented in the General Chemistry laboratory curriculum; this experiment was used for the duration of the 2020–2021 academic year. These experiments are suitable for all undergraduate experience levels.

Goals for the Undergraduate Instructional Inorganic Chemistry Laboratory When Course-Based Undergraduate Research Experiences Are Implemented: A National Survey

Course-based undergraduate research experiences (CUREs) are a promising approach for incorporating inquiry-based instruction into the undergraduate chemistry laboratory curriculum. This study used data from a national survey of inorganic chemistry faculty members (n = 142) to investigate CURE implementation in the inorganic chemistry instructional laboratory. Results indicate that faculty members who implement CUREs place greater emphasis on a distinct set of instructional goals when compared to faculty members who do not implement CUREs. CURE implementation was further associated with a range of instructional and departmental characteristics, including group-only student work, independent course development by faculty instructors, limited graduate TA support, and ACS certification of degree programs. Findings from this investigation point toward (1) a need for increased efforts focused on supporting CURE implementation, (2) productive avenues through which curriculum designers and communities of practice can provide this support, and (3) needed areas of research that will further inform these efforts.

Using Donor–Acceptor Stenhouse Adducts to Teach Photochromism in the Undergraduate Laboratory

There has been dramatic growth in interest and research regarding organic photochromism in recent decades. Despite this, the topic is seldom addressed in the undergraduate chemistry curriculum. Herein, we present a straightforward and robust experiment for the second semester organic chemistry laboratory curriculum which combines multistep synthesis, photochromism, and optical characterization. Over the course of a three-step synthesis, students prepare both the open and closed isomers of a Donor–acceptor Stenhouse adduct. At each stage of the synthesis, the pure products are isolated by filtration and characterized by traditional means (FTIR, 1H NMR). Additionally, students collect UV–vis data on the photoisomerization process and use this to calculate kinetic parameters. An inquiry-based variant of the experiment is also presented.

Simple Approach to Incorporating Experimental Design into a General Chemistry Lab

In an idealized General Chemistry Laboratory curriculum, students would hone their experimental design ability with practice encouraged by laboratory exercises designed to be open-ended. However, traditional General Chemistry Laboratory courses often lack opportunities for students to design their own experiments, instead opting to provide students with predetermined protocols. In addition, introducing guided inquiry into a General Chemistry Laboratory is logistically challenging, often prohibiting implementation. Here, we present a method for converting a traditional “cookbook-style” laboratory curriculum into one that is more open-ended with opportunities for students to practice experimental design skills. Our approach involves developing clear learning objectives, evaluating the existing curriculum for alignment to those objectives and providing opportunities for incorporating experimental design, and revising existing protocols. These revisions adopted a two week model, following up a traditional cookbook-style exercise focused on teaching students a given technique with a second week where students designed their own experiments to answer an instructor-provided question situated in a real-world context. This design provided sufficient structure for students to learn basic chemistry laboratory techniques while also creating the opportunity for practicing science process skills such as experimental design. Students in a pilot group experiencing this revised curriculum reported greater increases in their confidence with experimental design than peers in the traditional curriculum. We propose that this model could be adopted by other institutions as a meaningful step toward fully open-ended laboratory courses while avoiding many of the associated challenges.

Implementing an Iterative and Collaborative Approach to Inclusive First-Semester General Chemistry Laboratory Redesign

General chemistry laboratory curriculum reform is underway at a midsized state university through a collaborative, inclusive, and iterative approach. Using a backward design approach, faculty collaborated to actualize a shared vision, define laboratory learning objectives, and outline considerations for inclusivity during summer workshops that guided the process of curriculum design. With support from an instructional designer from the Center for Innovative Teaching and Learning, as well as faculty development support through an HHMI Inclusive Excellence grant, the faculty have designed and implemented the new curriculum, assessed the implementation, and continue to make iterative change based on student data and reflection. The goal of this report is not to provide a new set of chemistry laboratories, rather, we share our framework to provide an example of how to implement a collaborative and inclusive laboratory redesign.

Demonstrating More Realistic Research Outcomes to Undergraduates in the Organic Teaching Lab: Separation of Product Mixtures, Structure Analysis, and Mechanistic Inquiry

How well does the undergraduate organic chemistry laboratory curriculum prepare students for academic research, or for a bench job in industry? Running experiments that are more representative of research chemistry has the potential to better equip students for working in a research laboratory, while at the same time giving them insight into a typical outcome in a research project. We describe here an experiment that we have launched in the sophomore organic chemistry lab at UC Davis that presents challenges in chromatographic separation, structural assignment by NMR, and mechanistic interpretation. Optional exercises in computational modeling of the NMR data and chromophore analysis by UV–vis/fluorescence measurements are included.

Adapting Meaningful Learning Strategies to Teach Liquid–Liquid Extractions

Although teaching laboratories offer students the opportunity to act and think like chemists, in many cases students simply follow written procedures to generate predetermined outcomes. In recent years, there has been a movement toward inquiry-, problem-, and discovery-based learning. In a similar vein, the first-semester introductory organic chemistry laboratory curriculum at the University of Michigan was recently overhauled, informed by the strategies of meaningful learning. The new course consists of three interconnected modules, and we present herein the second module, which focuses on liquid–liquid extraction (LLE). In the first week, students learn how to perform LLE by designing their own separation of a dye mixture, gaining an understanding of how the solution pH impacts molecular structure and solubility. In the second week, they practice using LLE by designing a separation method to remove a pollutant from water, and then, in the third week, they apply LLE to isolate a reaction product. We assessed student learning through a writing assignment at the end of the three-week module. We also assessed how the overall course affects student understanding of LLE concepts and their confidence in the lab. Our findings suggest that this learn, practice, apply approach for teaching LLE leads to modest learning gains and increased confidence.

Developing a Green Chemistry Focused General Chemistry Laboratory Curriculum: What Do Students Understand and Value about Green Chemistry?

Over the past several decades, green chemistry has gained prominence in chemistry education. However, the development of green chemistry curricula has not reached all levels of education equally, f...

Synthesis of a Crosslinked Epoxy Resin Medallion in the Organic Chemistry Laboratory

Polymer synthesis has a limited inclusion in most organic chemistry lecture curricula, so emphasizing the concepts of polymer chemistry in a laboratory setting gives students hands-on experience in new content and broadens the scope of the class. The details and outcomes of a robust and well-developed laboratory procedure for the synthesis of a crosslinked epoxy network polymer are described. This experiment has been a part of a first-semester, introductory undergraduate organic chemistry laboratory curriculum for more than two decades and has positively impacted over eight hundred students. The experiment had the unique aspect that students cured the resin in a round, seven-centimeter mold, forming a hardened epoxy disk. This disk, or medallion, was decorated in two different ways: first, a design was etched into the mold before curing to form a permanent imprint; second, the final epoxy medallion was decorated, post-cure, with colored permanent markers and glitter glue. After this laboratory experiment, students took home a durable ornament as a memento of their first-semester organic chemistry laboratory course.

The Evaluation of a Hybrid, General Chemistry Laboratory Curriculum: Impact on Students’ Cognitive, Affective, and Psychomotor Learning

The laboratory has occupied an important place in the general chemistry curriculum for well over a century, despite the fact that many have voiced concern about its value and utility. In an effort to potentially increase capacity in our general chemistry courses, we developed and implemented a hybrid laboratory curriculum that consisted of alternating face-to-face and virtual laboratory experiments. This study sought to better understand the impact that this hybrid approach had on students’ cognitive, affective, and psychomotor learning. The results suggest that students taught using the hybrid approach developed similar cognitive and psychomotor skills in comparison to students taught using a traditional laboratory curriculum; however, their affective outlook toward chemistry was significantly lower.

Microwave-Promoted Synthesis of a Carbocyclic Curcuminoid: An Organic Chemistry Laboratory Experiment

A microwave-promoted synthesis of a carbocyclic curcuminoid has been developed for the undergraduate organic chemistry laboratory curriculum. The experiment features several teaching points: A nove...

Fruit and Vegetable Peels as Efficient Renewable Adsorbents for Removal of Pollutants from Water: A Research Experience for General Chemistry Students

Sustainability is emerging as a prominent curricular initiative at the undergraduate level, and as a result, involving students in real-world problems in the classroom and laboratory is an important goal. The specific problem of a dwindling supply of clean and safe drinking water is also of utmost importance and relevance. This general chemistry laboratory curriculum provides first-year students with an opportunity to design and implement their own experiments that employ fruit and vegetable peels as adsorbents to remove pollutants from water. The project is nine laboratory periods long, with the first 2 weeks devoted to providing students with the necessary tools to perform original research. In the third week, students visit the Dickinson College farm and brainstorm possible hypotheses. Working in pairs, students perform original research in the fourth through sixth weeks and investigate adsorption capacity and percent removal. In the final 3 weeks, students perform calculations and engage in peer revie...

A green determination of an equilibrium constant: teaching new skills

Abstract The spectroscopic determination of an equilibrium constant is a classic experiment in the general chemistry laboratory curriculum. Here we describe a new version of this experiment, incorporating green chemistry practices into the general chemistry lab curriculum and directly teaching students about the principles of green chemistry. This lab studies the formation of the iron(III) salicylate complex ion, which is a more benign chemical system than the traditional iron(III) thiocyanate complex. A microtiter plate reader is used to reduce sample volumes, also giving students important experience using research-grade instrumentation. In addition, students gain more experience using adjustable manual micropipettors. Students responded positively to the lab, appreciating the green nature of the lab and the introduction of the plate reader, and student comments suggested that this lab successfully introduces green chemistry concepts to the general chemistry curriculum.

Enhancing Professional Skills Based on a New Chemistry Laboratory Curriculum and Teaching Practice

Enhancing Professional Skills Based on a New Chemistry Laboratory Curriculum and Teaching Practice

Preparing 4-Ethoxyphenylurea Using Microwave Irradiation: Introducing Students to the Importance of Artificial Sweeteners and Microwave-Assisted Organic Synthesis (MAOS)

In today’s world of instant coffee, instant meals, and instant messaging, undergraduate students prefer not to have to wait 30–60 min for an organic reaction to take place. Heating with microwaves is rapidly becoming more commonplace due to dramatically reduced reaction times and higher product yields. Students appreciate the short reaction times and like working with advanced technology by means of the commercial microwave reactors available today. Furthermore, undergraduate organic students like being able to relate an experiment to something that they see every day. For these reasons, the synthesis of pharmaceuticals, extracting caffeine from tea, and isolating trans-cinnamaldehyde from cinnamon sticks are popular experiments. One such experiment is the synthesis of the artificial sweetener dulcin (4-ethoxyphenylurea), which can be prepared from the reaction of p-phenetidine and urea. Artificial sweetening agents are extremely important to the food industry because of the national concern with diet and weight control. The synthesis of this particular sweetener typically takes at least 30 min to reach completion. However, using microwave irradiation, the reaction reached completion in 5 min using a temperature of 125 °C. This procedure was implemented into the second semester undergraduate organic chemistry laboratory curriculum where students successfully prepared dulcin with reported yields ranging from 10% to 86% and an average yield of 39% after recrystallization.

Characterizing Instructional Practices in the Laboratory: The Laboratory Observation Protocol for Undergraduate STEM

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). ...

University Students’ Understanding of Chemistry Processes and the Quality of Evidence in their Written Arguments

Background:We have developed a process-oriented chemistry laboratory curriculum for non-science majors. The purpose of this study is to explore university students’ understanding of chemistry processes -- i.e., how chemical knowledge and products are constructed and used -- and to evaluate the quality of evidence students use to support their claims regarding chemistry processes in a process-oriented chemistry laboratory course.Material and methods:The data were collected from four classes offered during the first two semesters in which the new curriculum was implemented. We analyzed students’ written laboratory reports, which included the components of claims, evidence, and reflection, to investigate their understanding of the process skills required in knowledge construction in chemistry. We also evaluated the quality of evidence the students used to support their claims regarding chemistry processes by using five-level criteria which we developed.Results:The findings of this study show that a process-oriented laboratory curriculum contributes to developing university students’ understanding of chemistry processes and the ability to link appropriate and sufficient evidence to their claims.Conclusions:The findings of this study also imply that there are specific types of process skills which are unique or more necessary for chemistry research, and these skills can be developed through a process-oriented chemistry laboratory curriculum.