Journal of Chemical Education最新文献

In the past decade, researchers have been concerned aboutthe “replicationcrisis” in which a high number of studies have not been ableto be replicated. Conducting replication studies serves an importantrole in contextualizing the research in our field, but they are oftenoverlooked given that resources and incentive structures typicallyfavor “novel” and “original” work. Inthis article, we revisit a previous research project with the intentionof conducting a replication study. Specifically, we revisited ourown previous work that analyzed biochemistry students’ responsesto open-ended exam questions involving graphical reasoning relatedto enzyme kinetics. Using this framing, we build a case for “replication”within the assumptions of qualitative research, contextualizing ourwork in relation to tenets of dependability, credibility, transferability,and confirmability. We also discuss the context of the replicationstudy, which was conducted within the scaffolded structured of a “DBERCURE” (discipline-based education research, course-based undergraduateresearch experience). Based on the flexibility of scope, minimal resourcesneeded, and bounded nature of the project, a DBER CURE can providea feasible and adaptable approach to authentically engage undergraduateresearchers in education research while serving as an ideal settingfor conducting replication studies.

Wereport a modified CREATE pedagogy (Consider, Read, Elucidatehypotheses, Analyze data, and Try Experiments) and implement it inan undergraduate medicinal chemistry course to address limitationsof traditional teacher-centered STEM education, particularly the insufficientcultivation of scientific thinking. Compared with the classical CREATEframework, the fifth step was redefined from “Think of thenext Experiment” to “Try Experiments”, therebyemphasizing hands-on practice and experiential learning. This approachshifts the instructional focus from passive knowledge acquisitionto the development of students’ competencies in reading primaryliterature, analyzing scientific data, and designing drug discoverystrategies. The course was structured around original research articlesrather than textbook-based instruction, with modular content organizedaround the theme of the design and development of quaternary ammoniumantibacterial agents, culminating in experimental validation of student-designedstrategies. The results show that students enhanced their abilityto analyze and synthesize complex literature and interpret scientificdata. Their understanding of the scientific process deepened fromtheoretical awareness to hands-on engagement, creating an integrated,cyclic skill set spanning literature analysis, experimental design,and experimental verification. In addition, students demonstratedenhanced scientific self-efficacy, increased interest in medicinalchemistry and the research process, and made positive gains in classroomengagement and teamwork, highlighting a scalable and effective pedagogicalframework for cultivating talent in medicinal chemistry.

Tollens’ test selectively oxidizes aldehydes whenmixesto Tollens’ reagent, [Ag(NH₃)₂]⁺, producing the characteristic silver mirror that serves as a qualitativeindicator of aldehyde functionality. We extend this visually strikingobservation based test beyond the test-tube to help students understandand correlate different dimensions of chemistry as a guided inquiry-basedlearning centered in a classroom setting, outside of conventionallaboratory setting. Students are introduced to various concentration-drivenmixing techniques that exhibit distinct nucleation and growth patternsduring the formation of a metallic silver mirror film, observablein real time by the naked eye, making inference dependent on the observer.Students analyze five distinct observations, with one observationcorresponding to each pre-performed experiment, which connects knowledgeof synthetic organic chemistry not only to redox principles and chromatographybut also to capillary action, diffusion, and the sublimation process.This activity also opens up a connection to a contemporary topic:oxidative carbon–carbon bond coupling reactions over traditionalfunctional group transformations. Thus, the “outside test tube”presentation of Tollens’ reaction provides a guided inquiry-basedlearning activity that promotes observation-based reasoning, conceptualunderstanding, and interpretation of reaction processes beyond conventionallaboratory instruction.

This study describes the development and evaluation ofthe ChemistryCapital (ChemCap) Questionnaire, an instrument designed to measuredomain-specific social and cultural resources in chemistry education.Drawing on the broader science capital framework, chemistry capitalexplores how students’ resources, dispositions, and socialnetworks specifically influence their relationship with chemistry.A pilot study was conducted with 352 lower and upper secondary schoolstudents in Sarajevo Canton, Bosnia and Herzegovina. Exploratory FactorAnalysis (EFA) supported a nine-factor model, identifying distinctdimensions for general extrinsic motivation and teacher-supportedextrinsic motivation. The final 62-item version demonstrated stronginternal consistency, with Cronbach’s alpha coefficients rangingfrom .793 to .959 across all subscales (self-concepts, individualstrategies, motivation, parental/guardian attitudes, family support,and teacher support). These findings provide evidence of the ChemCapQuestionnaire’s validity and consistency as a tool for understandingeducational inequalities and measuring chemistry capital, settingthe stage for subsequent confirmatory testing.

Temperature and pH are among the most familiar intensivevariablesin chemistry and biology and are typically introduced as smooth continuumquantities that can be assigned locally without ambiguity. Yet modernchemistry increasingly probes systems whose dimensions approach thoseof organelles, vesicles, enzyme active sites, and nanoscopic aqueouscompartments, where molecular discreteness and statistical fluctuationsbecome unavoidable. This article examines how continuum thermodynamicconcepts emerge from underlying molecular statistics and under whatconditions they begin to lose their classical interpretation usingintracellular thermometry and proton statistics as pedagogical examples.A central case study is the “hot mitochondrion paradox,”in which fluorescent thermometry experiments suggest mitochondrialtemperatures substantially higher (by several degrees) than the surroundingcytoplasm, whereas steady-state heat-diffusion models predict temperaturedifferences of only ∼10^–5 K. The pH exampleis even more striking. At physiological pH, a cell-sized compartmentmay contain tens of thousands of protons, whereas an organelle-sizedvolume may contain only tens, rendering pH a fluctuating proton-countingvariable rather than a smooth concentration field. Classroom discussionsof local equilibrium, thermalization, thermal baths, finite-size fluctuations,transient local heating, operational definitions of temperature andpH, and electronic temperature in quantum systems are suggested. Numericalexamples, scaling estimates, and student exercises are also included.The goal is to help students recognize that temperature and pH donot abruptly “fail” at nanoscopic scales; rather, theybecome statistical, time scale-dependent, probe-dependent, and operationallydefined quantities. The accompanying examples, discussion questions,and numerical exercises are intended for upper-level undergraduatephysical chemistry and related courses.

Using red cabbage as a pH indicator is a common experimentin primaryand secondary school science classes and even at-home experiments.The fun experiment, often used to spark young people’s interestin STEM, involves changing the color of pH-sensitive anthocyanin pigmentsin red cabbage juice using common household ingredients. We presentan advanced version of the classic experiment for use at the universitylevel. The lab is applicable for both biochemistry and food sciencestudents and can be conducted as an in-person lab or a remote experimentstudents can complete fully at home. The colorful visuals, whole foods,and simple, familiar ingredients effectively facilitate students’understanding of the complex concepts of pigment chemistry and acid–baseequilibrium. Students who participated in the lab demonstrated increasedconfidence in the subject matter, and improved scores on quiz questionsrelated to pH, acid equilibrium, and anthocyanins. Students conductingthe lab remotely reported the experiment was easy to perform, fun,and helped them to better conceptualize challenging course material.

A degreein chemistry opens doors to a wide variety ofvaluablecareers; however, these diverse opportunities may not be apparentto undergraduate students. Broadening student perspectives and promotinga sense of belonging within chemistry classes may lead students tofulfill chemistry-related careers. An interactive Careers in Chemistry module was developed for first- to fourth-yearchemistry students that highlighted a spectrum of traditional andnontraditional chemistry careers that diverse alumni have successfullypursued. This module strategically emphasized people-oriented aspectsof these careers to cultivate an interest and persistence within thechemistry field. A research survey collected student perspectiveson this module, their future chemistry course and career aspirations,their perceived chemistry grades, and an indication of their senseof belonging in chemistry. The findings demonstrate the value of the Careers in Chemistry module for student learning and persistencein chemistry and provide insight into student career aspirations andsense of belonging for educators.

To address the predominance of verification-based exercisesandthe limited opportunities for inquiry-based training in polymer chemistrylaboratory courses, this study developed a comprehensive instructionalexperiment that engages upper-division undergraduates in authenticscientific inquiry. The experiment spans the full sequence of “moleculardesign–controlled synthesis–structural characterization–propertyregulation–functional extension” and is conducted overthree experimental cycles. In the first cycle, students prepared linearamphoteric polyacrylamide through aqueous free-radical copolymerizationof acrylamide (AM), acrylic acid (AA), and either 2-(methacryloyloxy)ethyltrimethylammonium chloride (DMC) or 2-(acryloyloxy)ethyl trimethylammoniumchloride (DAC). Using a “collaborative grouping with focusedvariables” strategy, different groups investigated the effectsof reaction temperature, cationic monomer structure, reaction time,and initiator dosage on the apparent viscosity of the products. Inthe second cycle, hydrogels were prepared under the optimized conditionsidentified in the first cycle using poly(ethylene glycol) diacrylate(PEGDA) as the cross-linker, and the relationships among cross-linkercontent, network structure, and water uptake were examined. In thethird cycle, three fluorescent dyes were incorporated to prepare luminescenthydrogels and extend the materials toward potential optical applications.Finally, the entire class integrated the shared data from all groupsto construct a “synthesis condition–structure–property–function”relationship map and used laboratory reports to justify evidence-basedconclusions. From an educational perspective, students shifted fromfollowing prescribed procedures to actively proposing hypotheses,controlling variables, and interpreting FT-IR and ¹H NMRspectra, while gaining experience with synthesis, characterization,and property-testing methods commonly used in academic research andindustrial development. Assessment using rubrics aligned with thethree learning objectives yielded attainment values of 0.78–0.84,exceeding the benchmark of 0.70, indicating effective improvementin multivariable experimental design, data integration, scientificreasoning, and teamwork. The individual modules can be adjusted orsimplified according to available class time, laboratory resources,and student preparation, making the experiment suitable for third-yearand more advanced undergraduates and adaptable to polymer laboratorycourses at different instructional levels.

Chemistry is often perceived as distant and challenging,whichcan limit public interest and engagement. Hands-on demonstrationsoffer a way to make chemistry accessible, engaging, and visually appealing,while also enhancing participants’ perception of learning.This article presents a do-it-yourself (DIY) luminescence workshopusing only common household materials, designed for high school studentsand the general public. Built around visually striking experimentsillustrating luminescence phenomena, the workshop aimed to achievefive outcomes: engagement and enjoyment, perceived conceptual understanding,increased interest in chemistry and science, DIY transferability,and a strong wow effect. Its impact was evaluated using a questionnaireaddressing enjoyment, interest, perceived understanding of luminescenceand fluorescence, and willingness to replicate experiments or engagewith science beyond the workshop. Results indicate high levels ofenjoyment and interest, a perceived improvement in understanding keyluminescence concepts, strong motivation to replicate experimentsat home, and a compelling wow effect─confirming that simple,safe, and accessible experiments can effectively foster interest inchemistry and support informal science learning without any specializedequipment.

Understanding hydrogen bonding and molecular interactionsin wateris crucial for various scientific disciplines, including chemistry,physics, and biology. While molecular models incorporating magnetsto simulate hydrogen bonding have been previously introduced, theirpotential as effective educational tools has not been fully explored.In this study, we present an educational activity that utilizes WaterPuzzle,a hands-on molecular model designed to help students explore hydrogenbonding and molecular interactions in water. This model allows studentsto physically assemble water molecules, observe the formation of hydrogen-bondnetworks, and explore ice crystal structures. Herein, we describethe scientific background, model design, and classroom implementationof this approach. Using WaterPuzzle, students can visualize and interactwith hydrogen-bond networks and explore structural aspects of waterthat are difficult to experience with traditional molecular models.