The top-ranking content of teaching is the core of first-class curriculum construction. This paper mainly introduces an example of teaching design for the first-class off-line course "Basic Chemistry Laboratory (Ⅰ)" at Xiamen University, which consists of the overall design and implementation about the laboratory teaching of "preparation, composition and impurity analysis, application of ammonium ferrous sulfate". The aim is to provide reference experience for the construction and the teaching reform of first-class course of basic chemistry laboratory.
Under the COVID-19 epidemic, online teaching has become a common choice for schools and universities across China. Focusing on the online course of "Physical Chemistry" offered by the College of Chemistry of Central China Normal University, this article presents the preparation of teaching materials, the choice of teaching platforms, the evolution of the teaching process, and our reflection on online teaching. Our teaching practice over the first half of the semester has taken the advantage of the affordances of digital technologies and brought into full playing teachers' role in providing guidance and students' initiative in learning. An online course has been collaboratively constructed by the teachers and students. Based on a survey on the students, this article discusses the merits and demerits of online teaching and implications for future online teaching practice.
Online teaching has been adopted by colleges and universities during the coronavirus disease outbreak. The problem for teachers and students is how to turn this crisis into an opportunity. Furthermore, it is important to ensure the quality of online teaching and explore new ways of teaching and learning. Therefore, a new form of online teaching of instrumental analysis course was developed using the combination of "SPOC + MOOC class + Tencent meeting + WeChat group." The practice of this new form of online teaching, that is, before class (guiding and helping), during class (teaching and studying), and after class (thinking and testing), shows a good teaching effect. In addition, it provides reference for online teaching.
Focusing on the interactive implementation and the evaluation of teaching, the BOPPPS teaching mode was extended from the class to the pre-and post-class learning activities based on the Chaoxing Xuexitong App and QQ live broadcast to form a featured complete online BOPPPS teaching mode for organic chemistry under the situation of COVID-19. The effective interaction of online teaching was realized, and good teaching results were achieved. This online BOPPPS teaching mode has laid a foundation for the online curriculum teaching reform and the construction of "outstanding course" of organic chemistry.
At present, with the development of China's internet and information technology, the multimedia teaching has been paid more attention. It's the critical step that how to combine effectively the traditional classroom teaching with online teaching in the new situation to improve the university teaching quality. This paper explores and reforms the current teaching model of analytical chemistry, and builds an online + offline blended teaching mode that includes four sections: preparation, preview, teaching and teaching reflection. Furthermore, this paper proposes a comprehensive evaluation system throughout the entire teaching process, and finally puts forward some suggestions for the problems of the blended teaching mode.
According to the characteristics of college organic chemistry, this article introduces the essence and practical significance of teaching of the "reflection and discussion method" with examples, particularly focusing on main forms of the "reflection and discussion method" from the perspective of students' "learning" and teachers' "teaching". I hope this will help fully cultivate students' learning initiative, creativity and solid basic skills, and I also hope to explore a new strategy and method for teaching of organic chemistry in universities, to obtain high-quality teaching results.
The concept of "thought experiment" is to imagine the complete experimental process, possible phenomena and corresponding operations before the experiment. We use this concept to design the teaching activities of organic chemistry laboratory by combining the theoretical knowledge and basic laboratory skills the students have learned. The "thought experiment" making is embedded into the learning process of basic research abilities such as the use of ChemDraw software, PPT production, professional literature retrieval and summary, reading and expression. This paper introduces our explorations in detail on how to use "thought experiment" to cultivate students' scientific literacy in teaching of organic chemistry laboratory.
As the key to the engineering field for chemical engineering undergraduates, chemical engineering principle undertakes the dual educational task of engineering science and engineering technology. Starting from the characteristics of chemical engineering principle, it takes unit operation as the foundation and research-oriented topics as the lead-in point. Students present the problem solving process through flipped classroom, from simple to deep, from daily life to production practice. This course also Integrates the curriculum design to improve the comprehensive ability and cooperation ability.
As the emerging renewable energy, biomass energy is the fourth largest energy next to coal, oil and natural gas. Alkyl levulinates are high value-added products obtained from biomass resources, which are an important class of chemical intermediates and new energy chemicals. The application of alkyl levulinates is very broad and has potential commercial value. This article introduces the physicochemical properties and uses of levulinates, together with three synthetic methods and reaction mechanism for preparing alkyl levulinates using biomass resources as raw materials. Finally, the deficiencies of alkyl levulinates production and application is analyzed, and the development trend of the future development and utilization of alkyl levulinates is provided.
Great progress has been made in N-heterocyclic carbene (NHC) catalyzed. In the reaction, NHCs are mainly used for the umpolung of aldehydes from electrophilic to nucleophilic. In this paper, the NHC-catalyzed nucleophilic substitution is described in detail; the umpolung of aldehyde and the corresponding substrate react through SN1, SN2, SN2', addition-elimination, elimination-addition processes. The introduction of the substitution reaction of aldehyde as a nucleophile can enrich and extension the content of the knowledge of aldehyde with ketone in undergraduate curriculum. It is also helpful for the students to understand the cutting-edge development of the discipline, and stimulate students' interest in exploration and learning.
Solution crystallization is an important process in crystal growth and industrial production. In this review, the basic principle and process of solution crystallization method were introduced, in which the concept of supersaturation was highlighted, and several factors influencing this process were put forward. Furthermore, a collection of conventional and emerging methods and techniques of solution crystallization were summarized based on the single or composite factors affecting solution supersaturation, including their basic experimental principles, operating procedures and typical cases of the application. Finally, the optimal design of crystal process under solution crystallization was discussed using 5W1H method.
The hydroboration-oxidation of 1-alkynes is important in fundamental organic chemistry. As an extension, this paper introduces the boration-migratory addtion-oxidation and boration-oxidation of 1-alkynes, which are closely related to yet more advanced than the knowledge of fundamental organic chemistry. The former one reaction converts 1-alkynes to aldehydes, while the latter two to ketones, caroboxylic acids, esters, and amides. Teaching these three types of reactions is helpful to improve the students' knowledge reserves and cognitive ability.
In this paper, we discussed the basic elements which affect the shape of linear sweep voltammograms in the reaction process on the electrode surface, that is, heterogeneous electron transfer and mass transfer in liquid phase. Derived from the basic definition and principle of voltammetry, the "supply-demand" mode between electron and mass transfer determines the characteristics of voltammograms. A series of voltammetric behaviors under different electrochemical testing conditions were discussed, including conventional electrodes and microelectrodes, reversible and irreversible electrode processes, stationary and rotating disk electrodes, and electrocatalysis. The basic laws that affect the shape of voltammograms provide a reference for understanding the fundamental principles of linear sweep voltammetry and data analysis.
(2R, 3R)-1, 4-dimethoxy-1, 1, 4, 4-tetraphenylbutane-2, 3-diol has diverse applications in asymmetric organic synthesis, and this paper briefly introduces the progress on its synthetic methods from the perspective of green chemistry. Our group developed new synthetic methods based on the region-selective transformation of (2R, 3R)-1, 1, 4, 4-tetraphenylbutanetetraol. In the preparation, methanol was used as a methylating reagent and common inorganic alkali liquor was used instead of DDQ and LiAlH4.
A detailed dynamic management system of chemicals has been created based on radio frequency identification (RFID) technology and face recognition in the National Demonstration Center for Experimental Chemistry Education of Xiamen University. The system is designed to track chemicals from their procurement, through their depletion and the disposal of empty bottles. It has been proved to be of high accuracy, easy operation and high reliability. The data recorded improve traceability in chemical management, and the data analytics provides guideline for ordering of chemicals. The system can be extended to manage the entire life cycle of chemicals from their manufacturing, storage, transportation, utilization and disposal as chemical waste.
This paper introduced an integrated experiment focused on the preparation technology of mesoporous nanomaterials for the undergraduate laboratory. A simple, efficient and highly controllable method was designed for one-step preparation of the hollow-structured PMO materials via growth-induced etching and layer-by-layer coating procedure. We reported the synthesis of monodispersed SiO2 nanpspheres and Hollow Periodic Mesoporous Organosilica (Et-HPMO). The morphology, pore structure and chemical properties of the composite materials are characterized by Infrared spectrum (IR), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The students can improve the systematic and comprehensive experimental skills by learning the design, preparation and characterization of series of PMO nanomaterials, which aims at enabling students to lay a good foundation in the advanced materials research.
This experiment elucidates a simple method for preparing and separating carbon quantum dots (CQDs), which were fabricated directly by using biological active substance of milk as the precursor and separated by adopting a new strategy of 'gradient extraction'. Furthermore, the relationship between the surface polarity of CQDs and their photoluminescence property are investigated. The aim of this experiment is to master hydrothermal synthesis and morphology characterization of nanomaterials, the principles and operations of analytical instruments including transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), and the data treatment methods. The purpose of the experiment is to cultivate students' general scientific research abilities, expand their scope of knowledge, and improve comprehensive capabilities for resolving practical problems by using related knowledge, in addition to mastering basic knowledge and laboratory skills.
This article introduces the application of smartphones in chemistry laboratory teaching in a comprehensive way. We summarize the characteristics of chemical experiment methods based on smartphones and the advantage of smartphones in chemistry laboratory teaching, and make an outlook of the application of smartphones in chemistry laboratories.
Hydride generation-atomic fluorescence spectrometry was applied to undergraduate experimental teaching to improve the knowledge of students. In this study, hydride generation-atomic fluorescence spectrometry was performed to detect arsenic in water samples. The best experimental conditions, such as the flow rate of the carrier gas, were investigated and optimized. The detection limit, quantification limit, and precision of the method were determined. Through the study of the course, students can master the working principle and operating method of hydride generation-atomic fluorescence spectrophotometry and grasp the quantitative analysis method of detecting arsenic through hydride generation-atomic fluorescence spectrometry. In addition, students can learn how to process and analyze experimental data and understand the working principles and application fields of different types of atomic spectrometry.
This paper mainly introduces the laboratory teaching experiment, preparation of trans/cis-[Co(en)2Cl2]Cl and determination of kinetic constants of their hydrolysis reaction, which has been carried out for 10 years and particularly designed for top-talented chemistry-majored students in Xiamen University. This experiment covers the basic theoretical knowledge such as the cis/trans isomers, the crystal field splitting energy and the hydrolytic reaction kinetics of the complex, and the experimental operation skills such as the preparation of cis/trans isomers, the spectral identification and the hydrolytic reaction kinetics research in different media. The purpose of this experiment was to let the students have a thorough understanding of the preparation of cis/trans isomers, the isolation and identification methods, and the methods of kinetic study on complex hydrolysis reaction. It is helpful for students to understand intuitively and profoundly that the structure determines property, to strengthen the deep integration of theory and experiment, as well as to cultivate the abilities of analysis, judging and critical thinking.
Owing to its mild, clean, and environmentally benign characteristics, visible light-induced photoredox catalysis in the past few years has emerged as a powerful tool to trigger organic transformations; however, it has not been introduced into the undergraduate laboratory teaching. 3, 3'-Bisindolylmethanes (BIMs) are privileged structural units that exist widely in numerous pharmaceutical active molecules. Moreover, BIMs are also important synthetic intermediates of numerous alkaloid natural products. Recently, we developed a visible light-induced aerobic oxidative cross-coupling reaction of glycine derivatives with indoles, which provides a straightforward access to BIMs. On the basis of this work, we designed a semi-microscale organic chemistry experiment for the efficient synthesis of ethyl 2, 2-di (1H-indol-3-yl) acetate, starting from ethyl (4-methoxyphenyl) glycinate and indole by using Rhodamine 6G as the photocatalyst under the irradiation of visible light at room temperature. The aims are to promote students to broaden their horizon of knowledge, establish the concept of "green chemistry" and awareness of environmental protection through the introduction of innovative scientific research into the laboratory teaching.
Chemical laboratories are inevitably exposed to hazardous chemicals, which can easily cause safety accidents, making personal injury and property damage. Therefore, hazardous chemicals have become one of the most serious hidden dangers in laboratories of universities. Combined with the work practice of management for hazardous chemicals in laboratories, especially from the practice of Shandong University, we put forward the concept of "green management" on hazardous chemicals based on the characteristics and existing problems of chemical laboratories. The idea of "green management" could provide examples as the management of hazardous chemicals in laboratories of universities.
From the point of cultivating research talents, the necessity of research teaching mode in the teaching process of basic chemistry experiment is expounded. Taking "sodium thiosulfate solution calibration experiment" as the teaching case, students were guided to actively explore, and comprehensively use the theoretical knowledge and technology. Selecting KIO3 as the basis material, the experimental conditions and end-point judgment methods were investigated from four aspects: acidity, water addition, reaction time and KI solution addition. The design and practice of research-oriented teaching in the process of basic chemistry experiment teaching is helpful to cultivate students' systematic research methods, rigorous scientific thinking, and the scientific literacy to explore and innovate.
The optical rotation measurement of the rate constant of sucrose hydrolysis reaction is one of the very classic chemical kinetic experiments in the university physical chemistry laboratory. In this paper, the addition of the optical rotation of the sucrose hydrolysis system, the reversibility of the sucrose hydrolysis reaction, and the effect of temperature on the reversible reaction equilibrium are discussed in depth. This article verifies the approximate processing in the current laboratory teaching, such as approximating the sucrose hydrolysis reaction as a first-order reaction, ignoring the reversed reaction, and the experimental conditions for obtaining the complete hydrolysis solution of sucrose. This article expands the teaching content of the sucrose hydrolysis experiment and deepens the students' understanding of optical rotation, chemical reaction order, thermodynamic dynamic balance and other knowledge.
The discoloration mechanism of spectrophotometric determination of trace manganese by ammonium persulfate oxidation is discussed in detail through experimental verification. The results show that hydrogen peroxide produced by the thermal decomposition of supersulfate ions leads to the discoloration of permanganate ions, using KIO4 instead of ammonium persulfate as oxidant to determine trace manganese can not only avoid the fading phenomenon of MnO4−, but also obtain accurate determination results.
In order to provide students with a more in-depth and intuitive understanding of the development and application of polymer materials in the field of nanotechnology, a comprehensive experiment was designed to focus on the design and biomedical applications of a novel-structured pH-responsive nanoparticle. This comprehensive experiment includes the synthesis of a pH-responsive block co-polymer via ring-opening polymerization, preparation of pH-responsive nanoparticles, and characterization and analysis of the polymer and the nanoparticles. This experiment helps students to understand the design principle and the basic processes of the preparation and characterization of polymer nanomedicine. This experiment involves the application of polymer science in the field of nanomedicine, which helps students to cultivate the ability to analyze and solve scientific problems, and stimulates the interest in exploring the frontiers of scientific research.
The general method and key points of obtaining t-plot with instrument software are introduced. The numerical processing method when there is no suitable film thickness equation and reference adsorption line is selected. The method and skill of converting isotherm adsorption line to t-plot with Origin software interpolation method is discussed.
Strychnine and Brucine are the two main alkaloids in the traditional Chinese medicine Strychnos nux-vomica L. However, the indiscriminate use of Chinese translations makes it difficult for the public to distinguish between Strychnine and Brucine. This has seriously affected the popularization of science and academic communications. We suggest uniform and strict annotations with these alkaloids' English names when the Chinese translations are used.
Nuclear magnetic resonance (NMR) is a frequently used spectral method for structural analysis of organic compounds. It is also an important content in the teaching of spectroscopy course. The principle of nuclear magnetic resonance involves some basic concepts including magnetic nucleus, nuclear spin, angular momentum, magnetogyric ratio, electric quadrupole moment, and the change of the internal nuclear energy level distribution in external magnetic field, etc. These concepts are important for the beginners to understand the principle of nuclear magnetic resonance. In this article, the attempt to rationally simplify the complex principle of quantum physics and elucidate the principle from the view of chemistry discipline, and to reasonably integrate ideological and political elements in teaching is discussed. This practice would not only help the students to understand the basic principle in depth, but also cultivate their scientific and systematical thinking and ability to solve complex problems.
The study aims to help students learn efficiently, summarize systematically, and apply knowledge comprehensively regarding the critical aspects of free radical polymerization. A comprehensive problem was proposed to develop their knowledge-comprehensive-application ability, questioning ability, problem-solving skills, critical thinking, and literature consulting awareness. The comprehensive problem, covering all the important aspects of free radical polymerization, was designed accordingly and assigned as team homework. Herein, a new form of problems in polymer chemistry is being developed, the function of problems in polymer chemistry is expanded, students' minds are being opened, and satisfactory results are being achieved.
Classroom introduction is the starting link of classroom teaching and plays a key role in the teaching effect of the whole class. Classroom introduction skill is an essential ability for pre-service teachers. Based on classroom observation and analysis of study cases, the author summarizes some typical problems of classroom introduction of pre-service chemistry teachers, such as simple stacking of situational materials, excessive use of negative materials, and tedious introduction design. In addition, attribution analysis is carried out from three aspects, namely, ignoring the function of introduction, insufficient understanding of subject value, and inadequate grasp of skill elements and designing principles. At the same time, combined with the analysis of demonstration cases, the countermeasures are put forward to guide the pre-service chemistry teachers to improve their classroom introduction skills.
This paper introduces a computer-aided instruction program package for teaching of acid-base titration and complexometric titration. The core parts of the package were programmed using C++ based on general expressions for acid-base titration and complexometric titration of arbitrary mixtures. The parameter file was designed to conduct operations of the software package. Users only need to write the parameter file according to a rule and then to calculate the titration curves of acid-base titration and complexometric titration of complicated system. A graphic user interface was developed to make it easy to implement the package. The package is helpful for the teaching of the theories of acid-base titration and complexometric titration.
In this work, the nature and characteristics of the thermodynamic energy and thermal capacity of real gas which obeys the equation of state p(Vm − b)=RT are introduced. The characteristics of thermodynamic parameters in isothermal process, adiabatic reversible process, Joule experiment, and throttling process are also discussed in detail. For a real gas, fugacity coefficient and the five of thermodynamic functions of the state are presented from chemical potential equation in isothermal process.
Kinetic data treatment is one of the paramount contents of the kinetics in physical chemistry. There have been imperfections in the classical kinetic data treatment when faced with modern monitoring techniques which can supply extensive experimental data. Recently, variable time normalization analysis is raised to solve the above problems. With only several experiments under real experimental conditions, the rate constant and reaction order of the reactants and catalyst can be deduced by using visual comparison with the help of spreadsheet.
There are many types of organic compounds, which have caused some problems in the teaching of organic chemistry. Understanding the structures of organic compounds, and thereby obtaining clarity on the properties of organic compounds, would improve the efficiency of teaching and learning. In order to understand the structures of organic compounds, it is necessary to be familiar with carbon atom hybridization and bonding in various organic compounds. In this paper, the aforementioned hybridization is briefly summarized in the order of sp, sp2, and sp3 hybridization.
The paper would revisit the classic story of ammonia synthesis and explore the untold details to get some hints about how an original idea or solution was produced in running research projects. There were generations of prominent scientists who had devoted to ammonia synthesis and failed with the loss of their fame, time or even lives. Fritz Haber accepted the challenge accidently, and confirmed a sound technological method that ammonia could be synthesized directly from its elements. Afterwards, his method was transferred successfully to the mainstream technology that influences the development of modern agriculture and society. The direct synthesis of ammonia has been used as one of the classic case studies of achieving original ideas or solutions by our graduate students in their professional careers. Furthermore, for the supervisors or service personnel in universities or research institutes, it would provide with an arsenal of spurring scientific discoveries or technological developments in graduate education programs.
In this paper, the synthesis of gold/(gold and palladium) heterojunction nanorods and the catalysis of 4-nitrophenol are introduced as a comprehensive and innovative experiment in physical chemistry specialty. Through this experiment which combined basic knowledge of physical chemistry and frontier sciences, undergraduates have mastered the abilities of consulting domestic and foreign literature, designing experimental contents and schemes, data processing and analysis methods, writing experiment reports, preparing PowerPoint slides and giving presentation. This innovative practice shows that this experiment is helpful to improve students' learning ability, thinking ability, execution ability, innovative consciousness and scientific spirit.
Organic-chemistry-related questions in the 33rd Jiangsu Province senior high school chemistry Olympiad selection contest are analyzed and elaborated upon in detail. To assist teaching, computational chemistry was utilized and served as a reference for instructors and participating students.