| 1. |
|
|
| 2. |
- Angelin, Marcus, et al.
(författare)
-
Making a Chemical Rainbow
- 2010
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 87:5, s. 504-506
-
Tidskriftsartikel (refereegranskat)abstract
- In this laboratory experiment, high school students are challenged to prepare a six-layered chemical "rainbow" in a test tube. Students start with six unknown, colorless liquids and six pigments ranging from violet to red. The experiment is problem based and forces the students to apply their knowledge of solubility and density and combine it with creative and critical thinking to come up with a successful strategy to make the rainbow. This is followed by experimental testing to find the unique solution. Finally, coloring and correct layering of the liquids produces the final and aesthetically pleasing result, a chemical rainbow.
|
|
| 3. |
- Angelin, Marcus, et al.
(författare)
-
Rocket scientist for a day : Investigating alternatives for chemical propulsion
- 2012
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 89:10, s. 1301-1304
-
Tidskriftsartikel (refereegranskat)abstract
- This laboratory experiment introduces rocket science from a chemistry perspective. The focus is set on chemical propulsion, including its environmental impact and future development. By combining lecture-based teaching with practical, theoretical, and computational exercises, the students get to evaluate different propellant alternatives. To complete the task, they need to use several important curricular concepts, such as the breaking and formation of bonds, redox reactions, and thermodynamics. They also apply basic computational electronic structure calculations to investigate the energetic content of hitherto nonexisting alternatives. Finally, actual chemical rocket propulsion is demonstrated through the assembly and testing of a model rocket motor, employing a commercially available kit. The full experiment was developed for upper-level high school classes and is completed in a 3-h lab period. The experiment, or parts of it, has also been successfully used both in undergraduate programs and continuing education for teachers.
|
|
| 4. |
|
|
| 5. |
- Benyahia Erdal, Nejla, et al.
(författare)
-
Polymer, giant molecules with properties : An entertaining activity introducing polymers to young students
- 2019
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 96:8, s. 1691-1695
-
Tidskriftsartikel (refereegranskat)abstract
- In this activity, polymer materials are introduced to 13–16 year old students. The activity is aimed at students with no or little knowledge of polymers. An engaging lecture covering the basics of polymer technology and sustainable development in the plastics field is presented. Important polymers such as polyethylene (PE), cellulose, and polylactide (PLA) are presented, and examples of their everyday use are shown. Quiz questions are employed in the introductory lecture to engage the students, to start discussions, and to evaluate the learning progress. The students are then engaged in two entertaining activities involving a natural polymer alginate and superabsorbent polymers. Alginate spaghetti is produced using different salt solutions enabling the students to create and destroy materials just by playing around with the chemistry, which helps them understand the polymeric material. The second activity has an application-based approach where the ability of superabsorbent polymers in diapers to retain water is investigated. The overall quiz results and discussions after the activities show an improved understanding of polymers and their applications and properties, making this activity useful for teaching polymers to young students.
|
|
| 6. |
- Bergendahl, Christina, et al.
(författare)
-
Boosting complex learning by strategic assessment and course design
- 2005
-
Ingår i: Journal of Chemical Education. - 0021-9584 .- 1938-1328. ; 82:4, s. 645-651
-
Tidskriftsartikel (refereegranskat)abstract
- A strategic selection of instruction and assessment methods geared to higher cognition levels was used to foster increasingly complex learning. Assessment results from the redesigned course show that students are capable of mastering higher-order cognitive skills relative to these objectives, however the synthesis category constitutes a threshold in students' cognitive development. No single assessment method was found to be clearly the best, yet careful selection of the method that allows higher-order thinking made it possible to develop a combination of assessments that meet objectives.
|
|
| 7. |
- Bergendahl, Christina, et al.
(författare)
-
Boosting complex learning by strategic assessment and course design
- 2005
-
Ingår i: Journal of Chemical Education. - Easton : Division of chemical education, American Chemical Society. - 0021-9584 .- 1938-1328. ; 82:4, s. 645-651
-
Tidskriftsartikel (refereegranskat)abstract
- Learning quality depends on the assessment methods used, as well as other factors. By choosing adequate assessments and involving students in the process of learning, students can gain a deeper understanding of the content and its context while developing related skills. In this study we describe a practical university-level biochemistry course that focuses on understanding protein separation and analysis techniques and especially on their application. The course was designed to examine the effects of a strategic use of differentassessment methods and an analysis of the resulting outcomes. We used quantitative as well as qualitative methods, including a simplified variant of the Bloom taxonomy, statistical methods, principle component analysis, inquires, and interviews. We conclude that astrategic choice of assessments and instructional design can be used to achieve morecomplex learning. We did not find any single teaching or assessment method to be clearly the best for enhancing higher-order thinking or achieving all learning objectives; rather a combination of different methods (i.e., a strategic choice) seems the best approach.
|
|
| 8. |
- Björk, Emma
(författare)
-
Synthesizing and Characterizing Mesoporous Silica SBA-15: A Hands On Laboratory Experiment for Undergraduates Using Various Instrumental Techniques
- 2017
-
Ingår i: Journal of Chemical Education. - : AMER CHEMICAL SOC. - 0021-9584 .- 1938-1328. ; 94:1, s. 91-94
-
Tidskriftsartikel (refereegranskat)abstract
- In this laboratory experiment, students learn how to synthesize mesoporous silica of the SBA-15 type and explore how the different synthesis steps affect the final material. Mesoporous materials, especially SBA-15, are often used in the development of new methods for. drug delivery, catalysis, and separation because of the flexibility of tailoring these materials to optimize the performance in different applications. However, the synthesis of mesoporous materials is rarely introduced to undergraduate students. The material synthesis is a simple sol gel process, where small alterations in the synthesis steps can significantly change the material characteristics. The presented laboratory experiment aims to introduce undergraduate students to the synthesis of SBA-15 mesoporous silica with different pore sizes due to alterations in the hydrothermal treatment time and/ or temperature and to give students hands-on experience with important characterization tools, including physisorption, X-ray diffraction, FTIR spectroscopy, and thermogravimetric analysis, to understand the effect of hydrothermal treatment and surfactant removal. Additional synthesis parameters to study, such as surfactant removal, the silica precursor, and pore swelling agents, are also presented. The experiment has been used in teaching of both bachelors and masters students and can be adapted to various instrumental techniques, e.g., scanning electron microscopy for morphology studies, transition electron microscopy for pore structure characterization, etc.
|
|
| 9. |
- Cedervall, Tommy, et al.
(författare)
-
Workshop on Environmental Nanosafety: Biological Interactions of Plastic Nanoparticles
- 2019
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 96:9, s. 1967-1970
-
Tidskriftsartikel (refereegranskat)abstract
- The one-hour workshop, containing both a demonstration and hands-on experiments on the topic of nanosafety, is based on current science on a topic of general interest. The workshop aims to provide a deeper knowledge and understanding of nanoparticles. The participants get an introduction to what nanoparticles are, why nanosized materials are interesting, how nanomaterials interact with biological molecules, and potential risks associated with nanoparticles. Furthermore, by participating in the workshop the audience gains insights into how research about nanoparticles is conducted. The participants carry out experiments to demonstrate that daily-used plastic products can be disintegrated into particles in the nanometer size range, which may have important implications for the environment.
|
|
| 10. |
- Cheung, Ocean
(författare)
-
Visualizing Gas Adsorption on Porous Solids : Four Simple, Effective Demonstrations
- 2014
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 91:9, s. 1468-1472
-
Tidskriftsartikel (refereegranskat)abstract
- Gas adsorption on porous solids is a topic that is often discussed in an undergraduate chemistry or chemical engineering course. The idea of porosity and gas adsorption on a porous solid is usually discussed with adsorption isotherms recorded using commercially available equipment. This discussion can be rather abstract and can be difficult for students to visualize. Here, four demonstrations highlight the adsorption of CO2 gas on adsorbents. These simple demonstrations show gas adsorption in a dynamic way that can help students understand the properties of porous solids.
|
|
| 11. |
|
|
| 12. |
- Cuartero, Maria, et al.
(författare)
-
Using Potentiometric Electrodes Based on Nonselective Polymeric Membranes as Potential Universal Detectors for Ion Chromatography : Investigating an Original Research Problem from an Inquiry-Based-Learning Perspective
- 2018
-
Ingår i: Journal of Chemical Education. - : AMER CHEMICAL SOC. - 0021-9584 .- 1938-1328. ; 95:12, s. 2172-2181
-
Tidskriftsartikel (refereegranskat)abstract
- Because traditional laboratory practices in advanced chemistry education are being replaced by inquiry based approaches, we present herein a new laboratory activity based on a small research project that was designed and executed by students. The laboratory project aims at answering a well-defined research question: how far can potentiometric electrodes based on nonselective polymeric membranes be used as universal detectors in ion chromatography (IC)? Hence, the experiments were designed and conducted to explore the analytical performances of potentiometric electrodes based on different commercial membranes that are typically used in electrodialysis. The nonselective behavior shown by the electrodes permits a critical evaluation of their further implementation as a universal detector of anions in regular IC. Thus, the students were able to integrate a nonselective potentiometric sensor to analyze several anions in flow mode, mimicking the signal that is to be obtained using such electrodes as an IC detector. The proposed practice covers different pedagogical purposes: (i) to develop competence toward "thinking like a scientist" through reflective teaching; (ii) to promote argumentation skills and critical decision making; (iii) to improve students' research-planning and experimental-design skills; (iv) to refresh conceptual knowledge about analytical detectors, which typically goes unnoticed in laboratory practices; and (v) to reinforce students' knowledge about the basis of potentiometry. Furthermore, the present document may serve as an easy guide to develop other laboratory practices based on potentiometric sensors.
|
|
| 13. |
|
|
| 14. |
- Elmgren, Maja, et al.
(författare)
-
Comparison and Evaluation of Learning Outcomes from an International Perspective : Development of a Best-Practice Process
- 2015
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 92:3, s. 427-432
-
Tidskriftsartikel (refereegranskat)abstract
- Chemistry education focused on learning outcomes is increasingly practiced, providing new opportunities for international comparisons. The interest in intended learning outcomes and constructive alignment has grown in many parts of the world due to both research in higher education and political decisions. In an International Union of Pure and Applied Chemistry (IUPAC) project, we have developed a method of using critical evaluation of learning outcomes and descriptors at international, national, and institutional levels to enhance learner-centered chemistry education. This method is process-focused, aimed at learning by sharing and comparing practices around the world. Three overarching documents for the chemistry bachelor from the USA, Europe and Australia were compared. The differences were found to be more in style than in content. A tool for self-analysis was constructed to evaluate how learning outcomes for courses and modules are linked to each other and to learning outcomes for educational programs and how the expected learning outcomes can be aligned with learning activities and assessment. We conclude that the method can be used to elucidate the correspondence between learning outcomes at different levels, and the constructive alignment between learning outcomes, learning activities and assessment. The process gives new perspectives and shared knowledge. Chemistry education may need to be different depending on local considerations, and awareness of these differences is of value for further development.
|
|
| 15. |
- Flynn, Alison B., et al.
(författare)
-
Future Directions for Systems Thinking in Chemistry Education : Putting the Pieces Together
- 2019
-
Ingår i: Journal of Chemical Education. - : AMER CHEMICAL SOC. - 0021-9584 .- 1938-1328. ; 96:12, s. 3000-3005
-
Tidskriftsartikel (refereegranskat)abstract
- The International Union of Pure & Applied Chemistry (IUPAC) launched a global project in 2017 to infuse systems thinking into chemistry education, motivated in part by the desire to help equip chemists and citizens to better address the complex, global challenges our society currently faces. One important early outcome of the IUPAC Systems Thinking in Chemistry Education (STICE) project is this special issue of the Journal of Chemical Education, which provides a key reference point for the rapidly emerging literature on the incorporation of systems thinking into chemistry education, including its application to green and sustainable chemistry. The STICE project outcomes to date include reviewing systems thinking approaches in other STEM fields, articulating a framework for STICE, identifying aspects of learning theories relevant to learning systems thinking skills in chemistry, using systems thinking approaches to integrate green and sustainability chemistry concepts into university-level chemistry classrooms, and identifying considerations for assessing systems thinking in chemistry education. The authors of this article, who, with others, have provided leadership to the STICE project, conclude this Journal's special issue by briefly reviewing progress to date and identifying three main areas of future work for the application of systems thinking in chemistry education: (1) developing systems thinking resources for chemistry educators and students, (2) identifying chemistry education research needed to investigate and improve systems thinking approaches, and (3) investigating opportunities to apply chemistry-related systems thinking approaches in broader educational contexts. Our intention is to recommend potential opportunities, stimulate conversations, and motivate actions required to successfully equip learners with systems thinking skills in chemistry, such that these learners, citizens of our countries and our planet, are better positioned to interpret and address complex global challenges.
|
|
| 16. |
- Fransson, Thomas, et al.
(författare)
-
eChem : A Notebook Exploration of Quantum Chemistry
- 2023
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 100:4, s. 1664-1671
-
Tidskriftsartikel (refereegranskat)abstract
- The eChem project features an e-book published as a web page (10.30746/978-91-988114-0-7), collecting a repository of Jupyter notebooks developed for the dual purpose of explaining and exploring the theory underlying computational chemistry in a highly interactive manner as well as providing a tutorial-based presentation of the complex workflows needed to simulate embedded molecular systems of real biochemical and/or technical interest. For students ranging from beginners to advanced users, the eChem book is well suited for self-directed learning, but workshops led by experienced instructors and targeting student bodies with specific needs and interests can readily be formed from its components. This has been done by using eChem as the base for a workshop directed toward graduate students learning the theory and practices of quantum chemistry, resulting in very positive assessment of the interactive nature of this framework. The members of the eChem team are engaged in both education and research, and as a mirroring activity, we develop the open-source software upon which this e-book is predominantly based. The overarching vision and goal of our work is to provide a science- and education-enabling software platform for quantum molecular modeling on contemporary and future high-performance computing systems, and to document the resulting development and workflows in the eChem book.
|
|
| 17. |
- Friedman, Ran
(författare)
-
Electrolyte Solutions and Specific Ion Effects on Interfaces
- 2013
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 90:8, s. 1018-1023
-
Tidskriftsartikel (refereegranskat)abstract
- Introductory general and physical chemistry courses often deal with colligative properties of solutions and do not discuss nonideal solutions in detail. Yet, a growing body of evidence reveals that even at physiological concentrations electrolyte solutions cannot be treated as ideal when a charged or partially charged solute (such as a protein) is present in the solution. In such cases, the interactions between the salt ions and the solute depend on the specific ions that constitute the electrolyte solution (specific ion effects). For example, the catalytic efficiency of an enzyme may be different in NaCl and KCl solutions. In this article, specific ion effects are reviewed from a historical perspective, and then the current state of knowledge is presented at a qualitative level that is appropriate for second-year or advanced undergraduate science students. Finally, the related nomenclature (Bjerrum ion pairs, Hofmeister series, lyotropic series, and specific ion effects) is analyzed, and some suggestions are made with respect to the terminology, to make it more accessible to students. The material is appropriate for courses where solution chemistry is discussed, for example, in physical chemistry. In addition, it may be included in the chemistry curriculum for life or pharmaceutical sciences.
|
|
| 18. |
|
|
| 19. |
- Ho, Felix M.
(författare)
-
Turning Challenges into Opportunities for Promoting Systems Thinking through Chemistry Education
- 2019
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 96:12, s. 2764-2776
-
Tidskriftsartikel (refereegranskat)abstract
- Systems thinking encompasses a set of skills forunderstanding, analyzing, and working with systems consisting ofmultiple interconnected elements and exhibiting emergent properties.Such systems are all around us, and helping students to develop suchskills is central to equipping them to tackle professional and societalchallenges. While the implementation of systems thinking approaches ineducation is increasingly widespread in disciplines such as biology,engineering, and geosciences, it is as yet not widespread in chemistry.This article aims to identify challenges in chemistry education that couldbe turned into opportunities for introducing concepts relevant tosystems and systems thinking, so that students improve their conceptualunderstanding of chemistry at the same time as they develop theirsystems thinking skills. Suggestions and examples of possible productivepedagogical approaches are also outlined and discussed.
|
|
| 20. |
- Holgersson, Stellan, 1964
(författare)
-
Hands-On Model of the Principle of Isotope Dilution Analysis for Use in an Interactive Teaching and Learning Classroom Exercise
- 2021
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 98:4, s. 1208-1220
-
Tidskriftsartikel (refereegranskat)abstract
- A simple hands-on model for illustrating the concept of isotope dilution analysis (IDA) has been devised. The model consists of two sets of beads of different sizes, with one set representing atoms of the analyte and the other set representing solvent water molecules. Phase separation is mimicked by sieving the beads, and the results are detected according to the color of the analyte beads. In this paper, the following three IDA methods are illustrated using the model: (1) direct IDA, (2) substoichiometric IDA, and (3) IDA-assisted neutron activation analysis. The model was demonstrated for a small group of graduate students with previous knowledge of nuclear chemistry, and the response from an inquiry held after the demonstration was good. It is suggested that the model can be used in a dry chemistry laboratory exercise to demonstrate the methodological differences between the different IDA methods, without the need for costly radioisotopes or irradiation facilities. It can also be used as a tool for engaging students in meta-modeling activities.
|
|
| 21. |
- Höst, Gunnar E., 1976-, et al.
(författare)
-
Students' Use of Three Different Visual Representations To Interpret Whether Molecules Are Polar or Nonpolar
- 2012
-
Ingår i: Journal of Chemical Education. - Washington, DC : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 89:12, s. 1499-1505
-
Tidskriftsartikel (refereegranskat)abstract
- Visualizing molecular properties is often crucial for constructing conceptual understanding in chemistry. However, research has revealed numerous challenges surrounding students' meaningful interpretation of the relationship between the geometry and electrostatic properties of molecules. This study explored students' (n = 18) use of three visual representations of electrostatic potential to interpret whether molecules are polar or nonpolar. The representations consisted of red and blue 'lobes' (termed RB) indicating regions of negative and positive potential, a color gradient mapping electrostatic potential on a molecular surface (MAP), and a rendering of the interface between regions of positive and negative potential (ISO). Data on students' accuracy, time-on-task, and evaluation related to the three visual modes were collected via a Web-based questionnaire. ANOVA indicated that students were significantly more accurate in interpreting ISO representations, although almost half evaluated this mode as the most difficult to use. Furthermore, students took significantly longer to interpret complex molecules than simple molecules using ISO and RB. The results indicate that there may be possible pedagogical benefits in using unconventional visual representations that reduce visual complexity by making molecular relationships explicit. Hence, this has implications for future work on the role of cognitively mapping between different instructional visualizations in the development of fundamental chemical concepts.
|
|
| 22. |
- Jansson, Stina, et al.
(författare)
-
Implementation of Problem-Based Learning in Environmental Chemistry
- 2015
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 92:12, s. 2080-2086
-
Tidskriftsartikel (refereegranskat)abstract
- Environmental Chemistry covers a range of topics within the discipline of chemistry, from toxicology to legislation, which warrants interdisciplinary study. Consequently, problem-based learning (PBL), a style of student-centered learning which facilitates the integration of multiple subjects, was investigated to determine if it would be a more appropriate instructional method for teaching Environmental Chemistry than the traditional teacher-centered education model. This article describes the practical aspects of course development and implementation of PBL in a master’s level course in Environmental Chemistry. Overall, the results, which were collected from the initial two years of the course, indicated that the students were pleased and found PBL to be an efficient methodology for not only learning, but also acquiring an in-depth understanding of Environmental Chemistry. This is intended as a case-study with the target audience consisting primarily of high school and undergraduate chemistry teachers, but may also be useful for teachers in other subject areas with an interest in student-centered education.
|
|
| 23. |
- Johansson, Adam Johannes
(författare)
-
Inga Fischer-Hjalmars (1918-2008) : Swedish pharmacist, humanist, and pioneer quantum chemist
- 2012
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 89:10, s. 1274-1279
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A wide variety of questions can be asked about the molecules that compose the physical reality around us and constitute biological life. Some of these questions are answered by the science called biology, others find their answer in chemistry, whereas the answers to the most fundamental questions are only to be found in the theories of physics. Inga Fischer-Hjalmars (born Fischer) belonged to the rare group of scientists who asked questions of all these kinds. Her life and career is a fascinating story of devotion, strive, and an unyielding curiosity about nature. As a young pharmacist, she had a central role in the development of the local anesthetic Xylocaine (also known as lidocaine), but the major part of her career was dedicated to explain the biological, chemical, and physical properties of molecules using the most fundamental principles available: quantum mechanics. Inga Fischer-Hjalmars was a pioneer in applying quantum mechanics to chemical problems, and she became the first female professor in theoretical physics in Sweden. Beside her scientific work, Inga Fischer-Hjalmars was a human rights activist dedicated to the freedom of oppositional and Jewish scientists in the Soviet Union. For this engagement, she was awarded with the New York Academy of Science's Human Rights of Scientists Award in 1990.
|
|
| 24. |
- Johansson, Adam Johannes
(författare)
-
Teaching the jahn-teller theorem : A simple exercise that illustrates how the magnitude of distortion depends on the number of electrons and their occupation of the degenerate energy level
- 2013
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 90:1, s. 63-69
-
Tidskriftsartikel (refereegranskat)abstract
- Teaching the Jahn-Teller theorem offers several challenges. For many students, the first encounter comes in coordination chemistry, which can be difficult due to the already complicated nature of transition-metal complexes. Moreover, a deep understanding of the Jahn-Teller theorem requires that one is well acquainted with quantum mechanics and group theory. A comparatively simple way to illustrate the anatomy of the Jahn-Teller effect is presented here. Chemistry teachers are reminded of a sometimes forgotten aspect, namely, that the orbital degeneracy itself is not a sufficient criterion for the Jahn-Teller effect to appear, it is necessary that the occupation of the degenerate energy level is asymmetric. The article can serve as an introduction to the Jahn-Teller theorem, either as a lecture or as a computational exercise.
|
|
| 25. |
- Jones, Alan Wayne
(författare)
-
The Variability of the Blood/Breath Ratio and Its Impact on the Results of Breath-Alcohol Analyses: A Rejoinder
- 2024
-
Ingår i: Journal of Chemical Education. - : AMER CHEMICAL SOC. - 0021-9584 .- 1938-1328. ; 101:3, s. 715-717
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Journal of Chemical Education (JCE) recently published a letter to the editor by Dominick Labianca that was critical of methods of breath alcohol analysis because of biological variability in the blood/breath ratio (BBR) of alcohol (). His opinions deserve further comment and discussion. As background information, breath-alcohol instruments are used for two main purposes: (i) as a roadside screening test of driver sobriety and (ii) evidential quality instruments are used to generate evidence for prosecution of traffic offenders. Variations in the BBR are irrelevant in jurisdictions that enforce a statutory breath-alcohol concentration (BrAC) limit for driving, such as 0.08 g/210 L in USA. Such legislation makes it unnecessary to convert BrAC into the coexisting blood-alcohol concentration (BAC) for legal purposes. Variability in the BBR is explained by various physiological factors, such as lung function and the volume of breath discarded before a sample is captured for analysis. Moreover, BrAC is more closely related to ethanol concentration in arterial blood rather than cubital venous blood, which is the specimen used for analysis in forensic casework. In those jurisdictions that might convert BrAC into the coexisting BAC, the use of a 2100:1 BBR as a calibration factor underestimates the true venous BAC in the majority of cases.
|
|
| 26. |
- Josephson, Philip, et al.
(författare)
-
Student-Driven Development of Greener Chemistry in Undergraduate Teaching: Synthesis of Lidocaine Revisited
- 2019
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328.
-
Tidskriftsartikel (refereegranskat)abstract
- Green chemistry and sustainable development have become increasingly important topics for the education of future chemists, but the implementation of green chemistry into the chemistry curriculum requires significant efforts from teachers, especially in laboratory education. A student-driven development of a greener synthesis of Lidocaine was performed by three first-cycle, third-year students as a part of their B. Sc. degree project with the goal to implement the procedure in an under-graduate organic chemistry course. The students were merely provided with the framework for the project and were given the opportunity to independently develop the project based on an analysis of the 12 principles of green chemistry. The "greenification" of the Lidocaine synthesis by the three students led to several green improvements of the standard procedure, for example, (1) decreased reaction temperature, (2) solvent replacement, (3) fewer equivalents of the starting material (diethylamine) by the use of an inorganic bulk base, (4) use of catalytic amounts of potassium iodide to promote the Finkelstein reaction, and (5) a two-step one-pot procedure. Furthermore, one of the developed procedures was successfully implemented in a full-scale organic chemistry laboratory course.
|
|
| 27. |
- Kolesnichenko, Pavel V., et al.
(författare)
-
Viking Spectrophotometer : A Home-Built, Simple, and Cost-Efficient Absorption and Fluorescence Spectrophotometer for Education in Chemistry
- 2023
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 100:3, s. 1128-1137
-
Tidskriftsartikel (refereegranskat)abstract
- Investigating the optical properties of various chemical compounds using UV-vis spectrophotometers is an essential part of education in chemistry. However, commercial spectrophotometers are usually treated as "magic black boxes", where the dominant majority of optical elements are hidden "under the hood". This often limits understanding of the mechanisms behind the generation of spectral curves, which in turn may impede the ability to understand the limitations of the applied method and, in some cases, interpret the acquired data. In addition, the study of optical emission phenomena using fluorescence spectrophotometers is seldom implemented in educational laboratories due to the practical challenges and costs of the devices, which severely limit pedagogic access to this topic. For students to be more confident with these two basic spectroscopy techniques, we have developed a laboratory kit that provides a multifaceted learning experience. Starting with a basic exploration of an instrument assembly, it teaches, for example, such technical concepts as spectral resolution and detection sensitivity. More fundamentally, it enables deeper learning of the Beer-Lambert law and the notion of Stokes shift. The spectrophotometer is built from cost-efficient materials and is easily scalable, making it affordable for many educational laboratories. Due to a modular design, it is adaptable to various levels of education and has been successfully applied during high school-, undergraduate-, and graduate-level classes.
|
|
| 28. |
- Limpanuparb, T., et al.
(författare)
-
Blue Bottle Experiment: Learning Chemistry without Knowing the Chemicals
- 2017
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 94:6, s. 730-737
-
Tidskriftsartikel (refereegranskat)abstract
- The blue bottle experiment is a popular chemical demonstration because of its simplicity and visual appeal. Most papers on the topic focus on a new formulation or a new presentation, but only a few discuss pedagogical application for a full lab session. This article describes the use of this experiment in the first session of undergraduate chemistry laboratory at the Mahidol University International College: Practical activities are designed to foster critical thinking and student-centered learning during a four-hour lab session. The main theme of our teaching is scientific method. Students are encouraged to work with a peer to propose hypotheses and test them. With a series of guidances and hints from the instructor and group discussion, students can propose the reaction mechanism for the experiment without knowing the identity of the chemicals in the reaction. Procedures described in this article may be used elsewhere with minimal modification.
|
|
| 29. |
- Lundberg, Dan, 1975, et al.
(författare)
-
Hydrolysis of Surfactants Containing Ester Bonds: Modulation of Reaction Kinetics and Important Aspects of Surfactant Self-Assembly
- 2011
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 88:9, s. 1274-1277
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of self-assembly on the hydrolysis kinetics of surfactants that contain ester bonds are discussed. A number of examples on how reaction rates and apparent reaction orders can be modulated by changes in the conditions, including an instance of apparent zero-order kinetics, are presented. Furthermore, it is shown that the examples on reaction kinetics display parallels and connections to important physicochemical aspects of surfactant aggregates, namely, the "reservoir function" of micelles and the fact that the headgroup region of micelles constitutes an aqueous environment largely distinct from the bulk solution. The examples presented can be used in teaching organic as well as physical chemistry. The text is written with the intention to be largely self-contained, in order to make it accessible for readers with different background experience.
|
|
| 30. |
- Lundberg, Peter
(författare)
-
Educational NMR software
- 1997
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 74:12, s. 1489-1491
-
Tidskriftsartikel (refereegranskat)abstract
- A description of a compilation of computer programs (EduNMRSoft) suitable for teaching NMR at an introductory to advanced level is presented. Each program is categorised and described by function, hardware requirements, availability, author, and references in the list. The compilation is available in electronic form at http://www.chem.umu.se/divisions/fk/EduNMRSoft.html.
|
|
| 31. |
|
|
| 32. |
- MacDonald, Robert P., et al.
(författare)
-
An Interactive Planetary Boundaries Systems Thinking Learning Tool to Integrate Sustainability into the Chemistry Curriculum
- 2022
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 99:10, s. 3530-3539
-
Tidskriftsartikel (refereegranskat)abstract
- Sustainability has a molecular basis that suggests a central role for chemistry in addressing today’s challenges to Earth and societal systems, and this role requires educators to see chemical reactions and processes as integral parts of dynamic and interconnected systems. Despite this prospect, few accessible resources are available for students and educators to facilitate systems thinking in chemistry for sustainability. We have developed an interactive digital learning tool (https://planetaryboundaries.kcvs.ca) based on the Planetary Boundaries framework, which uses interactive visualizations to help users better understand Earth system sustainability challenges and helps chemists and educators connect substances, reactions, and chemistry concepts to sustainability science. The tool highlights the fundamental role that chemistry plays in regulating the individual biophysical Earth system processes and in determining their control variables. It incorporates key features of a systems thinking framework by illustrating the dynamic interconnections among the processes and their control variables and demonstrates change of the Earth system over time. Finally, the interactive tool provides educators with accessible entry points to support the integration of chemistry curriculum content with sustainability considerations.
|
|
| 33. |
- Mahaffy, Peter G., et al.
(författare)
-
Can Chemistry Be a Central Science without Systems Thinking?
- 2019
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 96:12, s. 2679-2681
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- What is the history and justification of the claim that chemistry is "the central science"? Are our students able to see and appreciate such centrality of the knowledge of chemistry in the curriculum as well as in its broader interconnections with other fields of study and with societal issues? In this editorial for the special issue Reimagining Chemistry Education: Systems Thinking, and Green and Sustainable Chemistry, we, as guest editors, highlight the case made in the collective contributions to the special issue that systems thinking, including green and sustainable chemistry, shows promise as an approach to help chemistry students zoom out from detailed and fragmented disciplinary content to obtain a more holistic view of chemistry and its integral connection to earth and societal systems. Indeed, we ask the following question: How can we as a community of chemists and chemistry educators live up to the claim of being practitioners of the central science if we do not equip our students to engage in systems thinking? We further invite the community to make use of and build upon the contributions in this special issue and participate in a paradigm change in chemistry education that will help prepare our students to be citizens and scientists who are better equipped to deal with the grand challenges in the world.
|
|
| 34. |
- Neel, Bastien, et al.
(författare)
-
Camping Burner-Based Flame Emission Spectrometer for Classroom Demonstrations
- 2014
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 91:10, s. 1655-1660
-
Tidskriftsartikel (refereegranskat)abstract
- A flame emission spectrometer was built in-house for the purpose of introducing this analytical technique to students at the high school level. The aqueous sample is sprayed through a homemade nebulizer into the air inlet of a consumer-grade propane camping burner. The resulting flame is analyzed by a commercial array spectrometer for the visible spectrum in the range of 350-1000 nm. The cost of the instrument is mainly given by that of the spectrometer and computer/projector. The obtained emission spectrum is characteristic of each individual atom, such as sodium (589 nm) and potassium (766 nm), or molecule, such as calcium hydroxide (554 and 622 nm). The readout signal (either peak height or peak area) is shown to be proportional to the sample concentration. Both qualitative and quantitative analyses may be performed with this robust and low-cost device. Samples can be rapidly changed, giving a 95% response time of under 3 s. The analytical figures of merit were characterized for calcium, potassium, and sodium in different water samples, and the resulting precision (standard deviation) for a 1 s acquisition time was typically on the order of 2%. Observed calcium levels were lower than expected because of the presence of refractory compounds, such as calcium phosphate or sulfate, that are difficult to fully atomize with the simple flame used here. Lanthanum(III) chloride was successfully used to increase the calcium response. The lower limit of detection for sodium was approximately 3 ppb and comparable to that of conventional commercial emission spectrometers.
|
|
| 35. |
- Nezhyva, Mariya, et al.
(författare)
-
Inquiry-based Learning of Proteomics and Metabolomics
- 2024
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 101:2, s. 521-529
-
Tidskriftsartikel (refereegranskat)abstract
- Given the rapid development of data-driven experimental procedures within the life sciences, it is important to equip students with proper skills and knowledge on how to obtain and interpret complex data. While laboratory exercises have for a long time been well established as a teaching method for life sciences, we consider there is room for improvement in how laboratory exercises are conducted. Hence, we designed a laboratory exercise course in which students at the graduate level in the European education system (M.Sc.) are challenged to pose their own biological question and write their own laboratory protocol for a proteomic study to investigate their hypothesis. Here, students are supported in their task with lectures and seminars that take them through the required details on experimental sample preparation, analysis with LC-MS, and proteomic data evaluation of biological function and relevance. According to student interviews, the inquiry-based learning concept we used here provided a deeper understanding of the laboratory protocols they wrote, according to which they eventually performed their own experiments.
|
|
| 36. |
- Olander, Jenny, 1972-, et al.
(författare)
-
Didactic Reasoning about Using Chemicals in Teaching Upper Secondary Chemistry
- 2023
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 100:1, s. 45-52
-
Tidskriftsartikel (refereegranskat)abstract
- Chemicals are characteristic of chemistry education practices at all educational levels. The aim of this study is to explore teachers‘ didactic rationales when reasoning about the use of chemicals in their teaching practice. Experienced upper secondary chemistry teachers in Sweden were interviewed about their considerations regarding why, when, and how they use (or do not use) chemicals, in particular, hazardous chemicals. A qualitative content analysis was conducted. The results reveal that the teachers’ reasoning about their uses of chemicals is multifaceted and draws on student learning, teacher perspectives, traditions, and practical conditions. The results may be used to support teachers’ didactic analysis when planning practical work in chemistry education, both in preservice teacher education and continuous professional development.
|
|
| 37. |
|
|
| 38. |
- Pedersen, Henrik
(författare)
-
Simple Chemical Vapor Deposition Experiment
- 2014
-
Ingår i: Journal of Chemical Education. - : American Chemical Society, Division of Chemical Education. - 0021-9584 .- 1938-1328. ; 91:9, s. 1495-1497
-
Tidskriftsartikel (refereegranskat)abstract
- Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a simple CVD experiment designed to give hands-on experience with this technique using common chemical laboratory equipment is outlined. The experiment is suitable for an upper-level or graduate course on inorganic chemistry, materials chemistry or materials science. In the experiment, crystalline thin films of titanium nitride (TiN) are deposited using titanium tetrachloride, hydrogen, and nitrogen gas in an experimental setup based on a tithe furnace and common safety flasks. Typically, crystalline TiN films with some incorporation of TiO2 are deposited in this experiment. The experiment has been used in the teaching of both master and doctorial students.
|
|
| 39. |
|
|
| 40. |
- Pullen, Sonja, et al.
(författare)
-
SolEn for a Sustainable Future : Developing and Teaching a Multidisciplinary Course on Solar Energy To Further Sustainable Education in Chemistry
- 2014
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 91:10, s. 1569-1573
-
Tidskriftsartikel (refereegranskat)abstract
- The high demand for the integration of sustainable topics into university curricula presents new challenges for the way chemistry is traditionally taught. New teaching concepts are required that consider and connect different disciplines to achieve a higher student awareness of the importance of these topics for humanity, the environment, and the future of our planet. This article describes a uniquely multidisciplinary graduate course on solar energy; the course may serve as an example of how to incorporate sustainable topics into chemistry programs, and as a starting point from which to build for others. It combines different scientific, industrial, political, and humanitarian approaches to the topic and provides a broad overview of one of the main future energy resources. New teaching methods are introduced, combined, and evaluated with respect to their effectiveness for a sustainable education within science and, in particular, chemistry. The success of this new course concept is demonstrated by high student satisfaction in a trial course evaluation and impressive exam results.
|
|
| 41. |
|
|
| 42. |
- Schönborn, Konrad J., et al.
(författare)
-
Visualizing the Positive−Negative Interface of Molecular Electrostatic Potentials as an Educational Tool for Assigning Chemical Polarity
- 2010
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 87:12, s. 1342-1343
-
Tidskriftsartikel (refereegranskat)abstract
- To help in interpreting the polarity of a molecule, charge separation can be visualized by mapping the electrostatic potential at the van der Waals surface using a color gradient or by indicating positive and negative regions of the electrostatic potential using different colored isosurfaces. Although these visualizations capture the molecular charge distribution efficiently, using them to deduce overall polarity requires students to engage in the potentially demanding process of interpreting the relative positions of electron-rich and electron-poor areas. We present a visual tool that could help students assign polarity by exploiting the unique topography of the interface between negative and positive regions of electrostatic potential surrounding a molecule. Specifically, the tool renders the electrostatic potential isosurface(s) of a molecule obtained when the isovalue is set at 0. Examples of polar and nonpolar molecules are discussed.
|
|
| 43. |
- Sjöström, Jesper, et al.
(författare)
-
Didaktik Models in Chemistry Education
- 2020
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 97:4, s. 910-915
-
Tidskriftsartikel (refereegranskat)abstract
- The decisions and actions that chemistry educators make regarding why, what, how, and when to teach certain content or implement a specific instructional activity are often guided, but also constrained, by explicit or implicit "didaktik models". These types of models direct our attention and actions when designing curricula, planning for instruction, or assessing the learning process. They also give educators a professional language when talking or reflecting about teaching and learning. When used systematically, didaktik models support the implementation of research-based instructional practices and are helpful in the professional development of educators. In this essay, we describe, analyze, and discuss the nature and utility of didaktik models in chemistry education and argue that it is critical for chemistry educators to recognize and reflect on the types of models that guide their work.
|
|
| 44. |
- Sjöström, Jesper, et al.
(författare)
-
Humanizing chemistry education : from simple contextualization to multifaceted problematization
- 2014
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 91:8, s. 1125-1131
-
Tidskriftsartikel (refereegranskat)abstract
- Chemistry teaching has traditionally been weakly connected to everyday life, technology, society, and history and philosophy of science. This article highlights knowledge areas and perspectives needed by the humanistic (and critical-reflexive) chemistry teacher. Different humanistic approaches in chemistry teaching – from simple contextualization to socio-scientific orientations to multifaceted problematization – are discussed. The latter is crucial for “critical chemistry teaching”, which includes both problematized content knowledge in chemistry and problematized knowledge about chemistry and chemistry education (about the nature of chemistry, its role in society, and the way it is communicated inside and outside the classroom). We illustrate how various facets of chemistry knowledge for teaching can be used to characterize different levels of complexity in the integration of the human element into chemistry education.
|
|
| 45. |
|
|
| 46. |
- Stefanov, Bozhidar I., et al.
(författare)
-
Demonstrating Online Monitoring of Air Pollutant Photodegradation in a 3D Printed Gas-Phase Photocatalysis Reactor
- 2015
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 92:4, s. 678-682
-
Tidskriftsartikel (refereegranskat)abstract
- We present a demonstration of online monitoring of gas-phase photocatalytic reactions. A cotton cloth impregnated with commercial titanium dioxide nanoparticles is used as a photocatalytic filter to clean air contaminated with a model pollutant. A fan forces air through the filter while it is irradiated by UV diodes. The concentration of the air pollutant is measured online by an inexpensive, commercially available semiconductor air quality sensor. The structural parts of the reactor were 3D printed in polylactide bioplastic. We provide all schematics, 3D printed model parts, hardware, firmware, and computer code of the reactor and control units. The device can be used for interactive learning of both gas phase photocatalysis and gas sensing, as well as in student laboratory classes for measuring air pollutants and their photodegradation. The experimental setup can also form the basis for a project work for chemical engineering university students, and it can be employed as a building block for development of other gas phase chemical reaction demonstrations.
|
|
| 47. |
- Stewart, Alexander F., et al.
(författare)
-
Chemistry Writing Instruction and Training: Implementing a Comprehensive Approach to Improving Student Communication Skills
- 2016
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 93:1, s. 86-92
-
Tidskriftsartikel (refereegranskat)abstract
- The ability of science undergraduate students to capably communicate course content and their understanding of scientific phenomena through writing has long been considered a problem. Effective methods for improving student writing skills are often fragmented and undertaken on a course-by-course basis rather than as a coordinated approach. This paper describes the implementation of a departmental effort to enhance and evaluate chemistry student writing in several upper-year laboratory courses. The program involves introducing extensive writing focused aspects to course assignments and reports and has impacted over 600 students during a six-year period. Student feedback has been exceptionally positive from undergraduates as well as graduate students who previously participated in the initiative.
|
|
| 48. |
- Svenberg, Linus, et al.
(författare)
-
Investigation of the Chemical Inhibition Effect of Ground Elder (Aegopodium podagraria) on Timothy (Phleum pratense)?Introducing High School Students to Analytical Chemistry and Chemical Ecology
- 2023
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 100:3, s. 1227-1236
-
Tidskriftsartikel (refereegranskat)abstract
- The understanding of analytical chemistry and its application in different areas of life science is something that should be encouraged for students studying chemistry, and also something that appeals to many students. Life science includes a vast variety of areas, out of which some are more easily approached in student projects. The chemical communication between organisms, such as plants, as described in chemical ecology is one example. It is therefore beneficial to offer students inquiry-based project work that allows them to explore, and gain a deeper understanding of, this discipline within the grand context that is chemistry. Hence, the present work describes the application of analytical chemistry using gas chromatography-mass spectrometry, including sample preparation for the study of chemical inhibitory (allelopathic) properties of compounds found in the plant Aegopodium podagraria. The questions posed to the students performing this project work were "What compounds can be found in the extracts of the plant?", "Are the extracts allelopathic?", and "Can you determine which compounds contribute to the possible allelopathic properties?". The reported results indicate that the extracts might have allelopathic properties and showed that the extracts contained compounds such as alpha-pinene and beta-caryophyllene. The identified terpenes were shown to have minor allelopathic properties by themselves but displayed an impact on the germination of seeds and length of the sprouts when applied as a blend. This project, and its results, proposes a framework for investigation of other plants and can be adapted to suit students at different academic levels.
|
|
| 49. |
- Timmer, Brian, et al.
(författare)
-
Simple and Effective Integration of Green Chemistry and Sustainability Education into an Existing Organic Chemistry Course
- 2018
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 95:8, s. 1301-1306
-
Tidskriftsartikel (refereegranskat)abstract
- Green chemistry and sustainable development have become increasingly important topics for the education of future chemists. The cross-disciplinary nature of green chemistry and sustainable development often means these subjects are taught in conjunction with other subjects, such as organic chemistry and chemical engineering. Herein, a straightforward and efficient approach for vertical integration of green chemistry concepts within existing undergraduate organic chemistry courses is shown. The gradual self-evaluation, "greenification", and reassessment of an organic chemistry course at KTH Royal Institute of Technology from 2013 to 2017 is described, with particular focus on the laboratory course and a novel green chemistry project designed to promote sustainability thinking and reasoning. The laboratory project, which can also be conducted as an independent organic chemistry laboratory exercise, required students to critically evaluate variations of the same Pechmann condensation experiment according to the twelve principles of green chemistry. The course evaluation shows that, after the modifications, students feel more comfortable with the topics "green chemistry" and "sustainability" and consider these topics more important for their future careers. Furthermore, the ability of students to discuss and critically evaluate green chemistry parameters improved considerably as determined from the laboratory project reports.
|
|
| 50. |
- Wadsö, Lars, et al.
(författare)
-
Isothermal Titration Calorimetry in the Student Laboratory
- 2011
-
Ingår i: Journal of Chemical Education. - : American Chemical Society (ACS). - 0021-9584 .- 1938-1328. ; 88:1, s. 101-105
-
Tidskriftsartikel (refereegranskat)abstract
- Isothermal titration calorimetry (ITC) is the measurement of the heat produced by the stepwise addition of one substance to another. It is a common experimental technique, for example, in pharmaceutical science, to measure equilibrium constants and reaction enthalpies. We describe a stirring device and an injection pump that can be used with a previously described isothermal calorimeter to perform ITC measurements. Two experiments are also described: an acid−base titration and the binding of Ba2+ to the macrocyclic compound 18-crown-6. These experiments visualize the difference between strong and weak interactions (large and small equilibrium constants) and introduce how reaction enthalpies and equilibrium constants can be calculated from titration calorimetric experiments.
|
|
