Journal of Chemical Education最新文献

The global energy transition requires a workforce inthe chemicalsciences and engineering capable of bridging the laboratory-to-industrytraining gap. This paper presents an international joint Project-BasedLearning (PBL) model involving undergraduate students from universitiesin Brazil and Ecuador, who collaborated on the conceptual engineeringdesign of large-scale green hydrogen production plants for the urbantransport sector. Following a PBL framework, three international teamsintegrated core chemical engineering principles with emerging technologiesby utilizing basis of design and engineering criteria, simulationtools, and economic indicators to assess project feasibility. Thepedagogical value of this model was evaluated through a student perceptionsurvey focusing on student-reported learning, in which 86% of participantsrecognized high perceived learning and 85.7% recommended the interuniversityformat, despite logistical and linguistic hurdles. Subsequently, thetechnical outputs were subjected to an external evaluation by an industrialexpert who validated the realism of the design bases and the rigorof the techno-economic assessments. The results suggested that whileinternational PBL initiatives challenge traditional curriculum structures,they can provide a pathway to bridge the gap between academic theoryand industrial reality. In doing so, the framework can foster thetechnical and transversal skills needed for future professionals tohelp lead the global energy transition. Ultimately, this study offersa proof-of-concept for an adaptable, international PBL framework thatcan be implemented across diverse institutional contexts and scaledto other fields of knowledge.

This experimental design is tailored for third-year undergraduatestudents majoring in chemistry and materials science. It integratesthe synthesis of the molecular organic photocatalyst 4CzIPN with itsapplication in energy-transfer photocatalysis into a continuous experimentalsequence. Students synthesize the molecular organic photocatalyst4CzIPN through a nucleophilic aromatic substitution reaction underanhydrous and oxygen-free conditions and apply it to the contra-thermodynamic E→Z isomerization of (E)-1-(4-methoxyphenyl)-3-phenylprop-2-en-1-one ((E)-4′-methoxychalcone) driven by visible light. Theexperiment strengthens interdisciplinary knowledge integration (inorganic,organic, physical, and analytical chemistry) while focusing on keyskills such as Schlenk-line operation, column chromatography purification,TLC monitoring, and NMR quantitative analysis. By analyzing the correlationbetween reaction mechanisms and the photophysical properties of thecatalyst, students gain an understanding of the crucial role of Dexterenergy transfer in achieving contra-thermodynamictransformations. This design utilizes visible light as a sustainableenergy source and enhances students’ in-depth understandingof green photocatalysis and energy conversion through modular training(synthesis, purification, isomerization, and mechanistic analysis).

Paracetamol is a well-known drug used as analgesic andantipyretic.The synthesis of paracetamol is an important experiment in the syllabiof secondary and postsecondary courses of different universities,world over. Generally, it is prepared by reacting p-aminophenol with acetic anhydride in the presence of a catalyticamount of pyridine and sulfuric acid. The usage of pyridine and sulfuricacid makes the synthesis hazardous and therefore, unsafe for students.Green chemistry is being taught as a core paper to secondary and postsecondarystudents, globally. Green chemistry approaches can be employed forthe laboratory synthesis of paracetamol, whereby the use of pyridineand acid can be avoided to make the reaction comparatively safer forstudents. Taking into account the importance of green chemistry approachesand the synthesis of paracetamol as a laboratory experiment, thispaper reports a facile and greener mechanochemical laboratory experimentfor the synthesis of paracetamol by reacting p-aminophenolwith acetyl chloride. The identification of the synthesized paracetamolwas ascertained by comparison of its physical properties (physicalstate, appearance, melting point, and solubility) and chromatographicproperties (thin-layer chromatography) with paracetamol extractedfrom Dolo-650 tablets. In addition, the identification of paracetamolwas ascertained by simple chemical tests (ferric chloride and oxidationwith potassium dichromate). This experiment serves as an interestinginstructive approach for understanding mechanochemical organic synthesis,green chemistry, drug extraction from solid dosage formulations, identificationof organic drugs from property comparison with standard drugs, andsimple chemical tests without using high-end characterization techniques.

GeneralChemistry I remains a gateway course for students in STEMfields, with many students dropping out of the course or switchingto non-STEM fields after an unsuccessful first semester. The purposeof this article is to provide a framework for improving student performancein general chemistry using direct instruction in study strategies,specifically generative learning strategies. Twelve video-based modulesteaching generative learning strategies applied directly to first-yearchemistry concepts were implemented with 149 students at an undergraduate-focuseduniversity during the fall 2023 and fall 2024 semesters. These modules,which were integrated into a course management system, provided instructionand engagement in six separate literature supported strategies andtheir direct applications to course chemistry content. Strategiesincluded comparing and contrasting diagrams, drawing, learning byteaching, making inferences, summarizing, and predicting via estimation.Use of these strategies provides insight into skills required formastery of first year chemistry and also establishes a mechanism forimplementing these strategies as a student support tool. The structureof these modules requires a small instructor time commitment afterinitial implementation and is a nonintrusive way to teach studentshow to apply study strategies to learning chemistry. Example coursematerial used in the video modules along with preliminary assessmentoutcomes, suggestions for implementation, and future study are provided.

Transport of ions across membranes or separators canresult inelectric potential differences that are sensed in most electrochemicalexperiments and impact the interpretation of the experimental results.To assist in comprehending the underlying causes and expected valuesof these electric potential differences, we designed, implemented,and evaluated hands-on laboratory experiments that were performedby undergraduate and graduate students in electroanalytical chemistrycourses. The experiments require that students construct a simpletwo-compartment electrochemical cell using plastic cuvettes, a polymericion-exchange membrane, two reference electrodes placed in aqueouselectrolytes that wet each side of the membrane, and a voltmeter ora potentiostat to measure the open-circuit potential between the electrodes.Open-circuit potentials measured between commercially available Ag/AgClreference electrodes report on total Donnan and liquid-junction potentials.These electric potential differences are dictated by the compositionof ions in each liquid electrolyte through interactions with the ion-exchangemembrane and porous frits at the tip of each reference electrode.When reference electrodes consist of wires immersed directly in theliquid electrolytes, measured open-circuit potentials include contributionsfrom Nernst potentials, which arise from electric double layer chargingat each electrode interface driven by chemical potentials of redox-activespecies in the liquid electrolytes. While these experiments are suitablefor most upper-level undergraduate students in STEM, the conceptsof Donnan and liquid-junction electric potential differences and chemicalpotentials are advanced enough to educate graduate students and seniorresearchers alike. Student feedback obtained using surveys administeredbefore and after the laboratory experiments provides additional guidanceto instructors who plan to implement these experiments.

A critical pedagogical challenge in polymer science isbridgingthe gap between theoretical concepts and their experimental validation.Herein, we present an integrated laboratory course designed to addressthis challenge by immersing students in a complete model construction-validationcycle. This course centers on experimentally determining the ρ-value(ρ = R_h/R_g), one of the key quantitative descriptors of macromolecular compactness,using light scattering techniques. Using a series of architecturallydefined samples, including linear chain and single-chain nanoparticles(SCNPs) with varying cross-linking densities, students performed staticand dynamic light scattering (SLS/DLS) to measure their radius ofgyration (R_g) and hydrodynamic radius(R_h). Through guided data analysis, includingconstructing Zimm plots, fitting correlation functions, and evaluatingthe appropriateness of analytical models, students actively engagedin the iterative process of scientific inquiry─operating instruments,processing raw data, and comparing results to theoretical predictions.This approach transforms the laboratory from a routine characterizationexercise into a coherent investigative experience that connects measurement,model-based analysis, and chemical insights of the structure–propertyrelationship.

This paper describes the development of a virtual experimentfromthe video collection “Chemistry Comes Alive!” publishedby the Journal of Chemical Education. The originalvideo materials were updated for enhanced accuracy and comprehensiveness.An online quiz with automated grading function was integrated, forminga complete experiment “Properties and Identification of HeavyMetal Ions”. The experiment can assist students in learningdescriptive chemistry and related chemical theories, while simultaneouslytraining their skills in observation, data collection, logical reasoning,and qualitative analysis. The experiment has been used in first-yearchemistry curricula across multiple universities in China as wellas in several national science outreach events. In particular, a problemderived from the experiment served as the first virtual practicalproblem in the history of the International Chemistry Olympiad (IChO2022).

Classical molecular dynamics is a theoretical methoduseful forinvestigating noncovalent intermolecular interactions and conformationalflexibility, enabling the simulation of processes such as aggregation/dissolutionand adsorption. Molecular dynamics and quantum chemistry are increasinglyintroduced in chemistry curricula, yet students may encounter difficultieswhen translating theoretical concepts into robust simulation protocols,particularly outside biomolecular systems. Here, we present a tutorialdesigned to guide students through the preparation, execution, andanalysis of the simulations of small organic molecules in nonaqueoussolvents, followed by the calculation of ultraviolet–visible(UV–vis) absorption spectra using time-dependent density functionaltheory. This tutorial focuses on several practical issues: obtainingforce-field parameters, building simulation cells, selecting ensembles,and interpreting critical simulation parameters. Custom solvent modelsare validated against reference density and radial distribution functions,demonstrating how selected observables can be used to assess simulationreliability. We illustrate the usefulness of molecular dynamics byshowing that molecular flexibility and solvent interactions broadenthe UV–vis absorption band of indigo in chloroform. This contributionis intended as a hands-on educational resource for upper-level undergraduateand graduate students enrolled in physical chemistry and computationalchemistry courses, as well as for Ph.D. students working in chemistry,physics, or material science, who are approaching molecular simulations.To support dissemination, we have released a ready-to-use packageon GitHub that includes solvent boxes and all the necessary filesand data for incorporating new molecules into GROMACS simulations: https://github.com/cippee/SolventSafari-for-GROMACS.

In this work, we explore the structureand charge distributionwithin carbonyl compounds. It is routine in textbook explanationsto attribute the relative reactivity of aldehydes and ketones to electron-donatingeffects of alkyl groups. The results of our computational study indicatethat the changes in charge distribution contradict the common textbookexplanations. Neither the inductive effect nor the hyperconjugationeffect of a methyl group lower the partial positive charge on a carbonylcarbon atom, and the incorporation of halogens adjacent to the carbonyldoes not increase the partial positive charge. We must attribute thestabilization exclusively to differing hyperconjugation effects, andwe use NBO analysis of hyperconjugation interactions to quantify therelative stabilization of carbonyl compounds by representative groups.As a result, there is an opportunity to develop a more coherent frameworkfor teaching carbonyl chemistry, which intersects with alkene reactivityand carbocation stabilization.

Anintegrated research-style experiment on the preparation, characterization,and photoelectric properties of realgar (As₄S₄) is developed to enhance the interest, hands-on skills and innovativeability of undergraduates. Initially, students prepared red crystalsof α-As₄S₄ by the solvothermal methodand characterized via modern spectroscopic techniques including X-raydiffraction, X-ray photoelectron spectroscopy (XPS), UV–visabsorption and Raman spectroscopy. Then, they tested photoelectricproperties of α-As₄S₄, revealing thatit shows remarkable photocurrent response under visible-light illumination.Finally, students made DFT calculations to further illustrate thephotoexcitation mechanism. Such experiment is beneficial to (a) deepenstudents’ comprehension of low oxidation state As(II), As–Asbonds, As···S weak interactions, polymorph and clusterstructure of α-As₄S₄, (b) improve theirhands-on skills, scientific thinking and innovative ability, and (c)stimulate students to explore the new photoelectric materials viaproperty study.