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2016 Volume 31 Issue 10
2016, 31(10): 1-9
doi: 10.3866/PKU.DXHX201606001
Abstract:
The "Borrowing Hydrogen" reaction between alcohols and amines is a green route for accessing new amines.The concept of" Borrowing Hydrogen "reaction,the origin,and important developments,as well as future directions for "Borrowing Hydrogen" reaction of alcohols and amines by homogeneous catalysis are described in the paper.
The "Borrowing Hydrogen" reaction between alcohols and amines is a green route for accessing new amines.The concept of" Borrowing Hydrogen "reaction,the origin,and important developments,as well as future directions for "Borrowing Hydrogen" reaction of alcohols and amines by homogeneous catalysis are described in the paper.
2016, 31(10): 10-13
doi: 10.3866/PKU.DXHX201601031
Abstract:
Inorganic chemistry laboratory is an important and fundamental course in universities.This paper introduced a heuristic teaching method which was used through the inorganic chemistry laboratory teaching.We encouraged students to practice innovation in a variety of means,and guided students to be good at thinking and to find and solve problems in the experiments.It was helpful to improve the comprehensive quality of the students.
Inorganic chemistry laboratory is an important and fundamental course in universities.This paper introduced a heuristic teaching method which was used through the inorganic chemistry laboratory teaching.We encouraged students to practice innovation in a variety of means,and guided students to be good at thinking and to find and solve problems in the experiments.It was helpful to improve the comprehensive quality of the students.
2016, 31(10): 14-18
doi: 10.3866/PKU.DXHX201602016
Abstract:
Sichuan University establishes teaching assistants of master candidates (AMC) for reform of "inquiry-small class" teaching.The tutor arranges the good teaching assistants to take part in the pre-service training of AMC,and guides all the graduate assistant students to participate in the training of "fine example mini lesson" and "interactive seminar mini lesson".As a result,the students' participation and training quality are improved.
Sichuan University establishes teaching assistants of master candidates (AMC) for reform of "inquiry-small class" teaching.The tutor arranges the good teaching assistants to take part in the pre-service training of AMC,and guides all the graduate assistant students to participate in the training of "fine example mini lesson" and "interactive seminar mini lesson".As a result,the students' participation and training quality are improved.
2016, 31(10): 19-22
doi: 10.3866/PKU.DXHX201602017
Abstract:
This paper summarized our practices on cultural construction in chemistry laboratory including laboratory environment,rules,management and spirit based on the characteristics of our center.
This paper summarized our practices on cultural construction in chemistry laboratory including laboratory environment,rules,management and spirit based on the characteristics of our center.
2016, 31(10): 23-28
doi: 10.3866/PKU.DXHX201602012
Abstract:
With the help of PHREEQC program,we introduced the application of computer simulation in theoretical and laboratory teaching of chemistry.Accordingly,reaction models for the chemical process of acid-base neutralization,complexation reaction,precipitation-dissolution equilibrium,and chemical kinetics were established.These models can greatly help the students understand chemistry,improve the teaching quality,enrich modern teaching methodology,develop students' creativity,and establish a scientific and efficient research method.
With the help of PHREEQC program,we introduced the application of computer simulation in theoretical and laboratory teaching of chemistry.Accordingly,reaction models for the chemical process of acid-base neutralization,complexation reaction,precipitation-dissolution equilibrium,and chemical kinetics were established.These models can greatly help the students understand chemistry,improve the teaching quality,enrich modern teaching methodology,develop students' creativity,and establish a scientific and efficient research method.
2016, 31(10): 29-34
doi: 10.3866/PKU.DXHX201602014
Abstract:
Common illustrations in inorganic and analytical chemistry course were summarized and catalogued in this paper.Mapping principles and applications were accordingly introduced focusing on flexible use and simplification of the knowledge.The purpose was to improve students' learning enthusiasm and initiative,in hopes that they can have an overall understanding and integrated use of knowledge in the course,and also provide a reference for the study of physical chemistry course.
Common illustrations in inorganic and analytical chemistry course were summarized and catalogued in this paper.Mapping principles and applications were accordingly introduced focusing on flexible use and simplification of the knowledge.The purpose was to improve students' learning enthusiasm and initiative,in hopes that they can have an overall understanding and integrated use of knowledge in the course,and also provide a reference for the study of physical chemistry course.
2016, 31(10): 35-38
doi: 10.3866/PKU.DXHX201602013
Abstract:
Based on the chromatography course,we discussed how to cultivate students' interest and creative ability by using heuristic teaching and research teaching mode.Some examples used during the practice were given in the paper.The practice has proved that both teaching modes are important for further improving students' knowledge.
Based on the chromatography course,we discussed how to cultivate students' interest and creative ability by using heuristic teaching and research teaching mode.Some examples used during the practice were given in the paper.The practice has proved that both teaching modes are important for further improving students' knowledge.
2016, 31(10): 39-43
doi: 10.3866/PKU.DXHX201602008
Abstract:
Based on the experience of bilingual teaching of the undergraduate course of polymer chemistry,the paper analyzed and discussed several important aspects that should be paid attention to in the bilingual teaching,including the objectives and significance of the bilingual teaching,the selection of Chinese and English text books,the text model of bilingual teaching and multimedia courseware making,the adjustment and optimization of teaching content,the optimization of bilingual teaching methods and the evaluation effect of bilingual teaching.These would provide good references for the teachers to improve the bilingual teaching level for both undergraduate and postgraduate students in the future.
Based on the experience of bilingual teaching of the undergraduate course of polymer chemistry,the paper analyzed and discussed several important aspects that should be paid attention to in the bilingual teaching,including the objectives and significance of the bilingual teaching,the selection of Chinese and English text books,the text model of bilingual teaching and multimedia courseware making,the adjustment and optimization of teaching content,the optimization of bilingual teaching methods and the evaluation effect of bilingual teaching.These would provide good references for the teachers to improve the bilingual teaching level for both undergraduate and postgraduate students in the future.
2016, 31(10): 44-48
doi: 10.3866/PKU.DXHX201601039
Abstract:
It is very helpful for the students to learn organic chemistry effectively by thinking on three levels,the macro,micro and symbolic representations,and building the internal relationship among them.In the paper,the teaching strategy of organic chemistry in university based on triple representations is discussed.
It is very helpful for the students to learn organic chemistry effectively by thinking on three levels,the macro,micro and symbolic representations,and building the internal relationship among them.In the paper,the teaching strategy of organic chemistry in university based on triple representations is discussed.
2016, 31(10): 49-53
doi: 10.3866/PKU.DXHX201602006
Abstract:
According to the knowledge system and requirements of analytic chemistry,the discussionbased teaching and organizing-based teaching are used to arouse the enthusiasm of each student's learning,deepen the understanding and using of knowledge,and improve students' comprehensive quality and ability.
According to the knowledge system and requirements of analytic chemistry,the discussionbased teaching and organizing-based teaching are used to arouse the enthusiasm of each student's learning,deepen the understanding and using of knowledge,and improve students' comprehensive quality and ability.
2016, 31(10): 54-56
doi: 10.3866/PKU.DXHX201511021
Abstract:
The overall goal,present situation and problems of chemistry laboratory course in universities were introduced.The management principles were applied in teaching of chemistry laboratory course in universities to improve the teaching effect.
The overall goal,present situation and problems of chemistry laboratory course in universities were introduced.The management principles were applied in teaching of chemistry laboratory course in universities to improve the teaching effect.
2016, 31(10): 57-59
doi: 10.3866/PKU.DXHX201508008
Abstract:
To improve the students' autonomous learning ability and learning enthusiasm in practice course,we introduce micro video,which is short,fast,precise,easy,and fun,into inorganic chemistry laboratory teaching.As an important supplementary means of teaching,micro videos will solve the repeated problems,help students promote study efficiency,provide students with a good way for communication,and improve the students' study enthusiasm.
To improve the students' autonomous learning ability and learning enthusiasm in practice course,we introduce micro video,which is short,fast,precise,easy,and fun,into inorganic chemistry laboratory teaching.As an important supplementary means of teaching,micro videos will solve the repeated problems,help students promote study efficiency,provide students with a good way for communication,and improve the students' study enthusiasm.
2016, 31(10): 60-63
doi: 10.3866/PKU.DXHX201602003
Abstract:
We discover the eutectic state in binary mixtures of fluorene-fluorenone.The melting temperatures of the solid mixtures with different fluorene/fluorenone ratios (mol percentage) are measured by the X-4 digital display micro melting point apparatus.The least-squares method is used to analyze the relations between the melting points and the mol percentage of fluorenone in binary mixtures.The temperature and the mol percentage of fluorenone at the intersection of two fitting straight lines are the eutectic point and eutectic composition of fluorene-fluorenone binary system,respectively.The eutectic point is found to be 57.4℃,and the mol percentage of fluorenone is 61%.This test method to determine the eutectic point of solid mixtures is suitable for undergraduate chemistry laboratory teaching.
We discover the eutectic state in binary mixtures of fluorene-fluorenone.The melting temperatures of the solid mixtures with different fluorene/fluorenone ratios (mol percentage) are measured by the X-4 digital display micro melting point apparatus.The least-squares method is used to analyze the relations between the melting points and the mol percentage of fluorenone in binary mixtures.The temperature and the mol percentage of fluorenone at the intersection of two fitting straight lines are the eutectic point and eutectic composition of fluorene-fluorenone binary system,respectively.The eutectic point is found to be 57.4℃,and the mol percentage of fluorenone is 61%.This test method to determine the eutectic point of solid mixtures is suitable for undergraduate chemistry laboratory teaching.
2016, 31(10): 64-67
doi: 10.3866/PKU.DXHX201601038
Abstract:
To cultivate students' innovation ability,we designed the synthetic method of benzyl benzoate as an organic chemistry laboratory experiment.Benzyl benzoate was directly synthesized from benzaldehyde in the presence of a sodium benzyloxide via the Tishchenko reaction.The experimental conditions are optimized with a benzaldehyde to sodium benzyloxide mole ratio of 33:1 and a 50-60℃ reaction temperature for 1 h.A yield up to 69% was achieved with the purity higher than 99%.The experimental results show that the process is in accordance with the requirements of organic chemistry laboratory teaching.
To cultivate students' innovation ability,we designed the synthetic method of benzyl benzoate as an organic chemistry laboratory experiment.Benzyl benzoate was directly synthesized from benzaldehyde in the presence of a sodium benzyloxide via the Tishchenko reaction.The experimental conditions are optimized with a benzaldehyde to sodium benzyloxide mole ratio of 33:1 and a 50-60℃ reaction temperature for 1 h.A yield up to 69% was achieved with the purity higher than 99%.The experimental results show that the process is in accordance with the requirements of organic chemistry laboratory teaching.
2016, 31(10): 68-73
doi: 10.3866/PKU.DXHX201601035
Abstract:
Taking the assumption that activity of silver ion and sulfate ion of very low concentration is constant in any aqueous solution,the primary cell was designed for the cell reaction of Ag2SO4(s)→2Ag+(aq)+SO42-(aq).The compensation method was used to obtain the electromotive force of the primary cell when the concentrations of AgNO3 and K2SO4 changed.The relationship between electromotive force and the mean activity coefficients of electrolytes as well as the solution concentration was deduced according to the Nernst equation and the limit Debye-Huckel formula.Standard electromotive force E ⊖ was obtained by extrapolation.Finally,the solubility product of silver sulfate was calculated through the relationship between equilibrium constant and electromotive force of the primary cell.
Taking the assumption that activity of silver ion and sulfate ion of very low concentration is constant in any aqueous solution,the primary cell was designed for the cell reaction of Ag2SO4(s)→2Ag+(aq)+SO42-(aq).The compensation method was used to obtain the electromotive force of the primary cell when the concentrations of AgNO3 and K2SO4 changed.The relationship between electromotive force and the mean activity coefficients of electrolytes as well as the solution concentration was deduced according to the Nernst equation and the limit Debye-Huckel formula.Standard electromotive force E ⊖ was obtained by extrapolation.Finally,the solubility product of silver sulfate was calculated through the relationship between equilibrium constant and electromotive force of the primary cell.
2016, 31(10): 74-79
doi: 10.3866/PKU.DXHX201601034
Abstract:
Three macrocyclic oxamide complexes were synthesized by reflux and solvothermal methods.The structures were determined by X-ray crystallography.The complexes were characterized by means of elemental analyses,IR spectra,electronic spectra and ESR spectra.The experimental raw materials are simple and easy to obtain.The experimental methods are simple and easy to operate.It can train students' practical and innovative abilities.
Three macrocyclic oxamide complexes were synthesized by reflux and solvothermal methods.The structures were determined by X-ray crystallography.The complexes were characterized by means of elemental analyses,IR spectra,electronic spectra and ESR spectra.The experimental raw materials are simple and easy to obtain.The experimental methods are simple and easy to operate.It can train students' practical and innovative abilities.
2016, 31(10): 80-83
doi: 10.3866/PKU.DXHX201601029
Abstract:
A comprehensive experiment was designed for laboratory teaching in this paper.The composition and content of chemical constituents in landfill leachate were analyzed by gas chromatography hyphenated with mass spectrometry (GC-MS).Through the analysis of the experimental results,the types and relative contents of organic pollutants in landfill leachate were determined.The application of this experiment to laboratory teaching can cultivate students' comprehensive analysis and testing ability,and improve students' ability of practice.
A comprehensive experiment was designed for laboratory teaching in this paper.The composition and content of chemical constituents in landfill leachate were analyzed by gas chromatography hyphenated with mass spectrometry (GC-MS).Through the analysis of the experimental results,the types and relative contents of organic pollutants in landfill leachate were determined.The application of this experiment to laboratory teaching can cultivate students' comprehensive analysis and testing ability,and improve students' ability of practice.
2016, 31(10): 84-88
doi: 10.3866/PKU.DXHX201603015
Abstract:
For oxidation of carbon in different temperature ranges,there is different temperature dependence of rate constant.The temperature dependence can be divided into two sections.The first section is mainly determined by the chemical adsorption of oxygen on the carbon surface,forming oxygencontaining surface complexes.The effect of temperature on adsorption equilibrium of oxygen results in the first increase and then decrease of rate constant with increasing temperature.For the second section,it is mainly influenced by gasification of carbon in carbon dioxide,in which desorption of the carboxyl group is the rate-determining step (r.d.s.).In this paper,a comparison among the formerly established mechanisms for carbon oxidation at high temperature was made and a simplified mechanism was put forward.The rate equation for the second section was deduced based on this new mechanism using r.d.s.approximation and pre-equilibrium approximation treatments.The deduced rate equation is in good accordance with the main experimental facts.Therefore,a satisfactory explanation is given for the unusual behavior of carbon oxidation.
For oxidation of carbon in different temperature ranges,there is different temperature dependence of rate constant.The temperature dependence can be divided into two sections.The first section is mainly determined by the chemical adsorption of oxygen on the carbon surface,forming oxygencontaining surface complexes.The effect of temperature on adsorption equilibrium of oxygen results in the first increase and then decrease of rate constant with increasing temperature.For the second section,it is mainly influenced by gasification of carbon in carbon dioxide,in which desorption of the carboxyl group is the rate-determining step (r.d.s.).In this paper,a comparison among the formerly established mechanisms for carbon oxidation at high temperature was made and a simplified mechanism was put forward.The rate equation for the second section was deduced based on this new mechanism using r.d.s.approximation and pre-equilibrium approximation treatments.The deduced rate equation is in good accordance with the main experimental facts.Therefore,a satisfactory explanation is given for the unusual behavior of carbon oxidation.
2016, 31(10): 89-94
doi: 10.3866/PKU.DXHX201512021
Abstract:
The old classification of basic chemical reactions was evaluated and a new systematic classification of basic reactions was proposed.In the new classification,all the chemical reactions were divided into oxidation-reduction reactions and non-oxidation-reduction reactions,and both can be divided into combination reaction,decomposition reaction and replacement reaction,respectively.In addition,a new class of basic reactions,the complicated decomposition reaction,was appended to reaction system.
The old classification of basic chemical reactions was evaluated and a new systematic classification of basic reactions was proposed.In the new classification,all the chemical reactions were divided into oxidation-reduction reactions and non-oxidation-reduction reactions,and both can be divided into combination reaction,decomposition reaction and replacement reaction,respectively.In addition,a new class of basic reactions,the complicated decomposition reaction,was appended to reaction system.
2016, 31(10): 95-97
doi: 10.3866/PKU.DXHX201512010
Abstract:
Television program has become one of young people's main entertaining fashion now,and is affecting young people's study.We consider that put the application of acid-base indicator in television program into education,let the student study the knowledge of chemistry in the television program,that may create an interesting learning environment for the learner,and is helpful in raising learner's study interest.
Television program has become one of young people's main entertaining fashion now,and is affecting young people's study.We consider that put the application of acid-base indicator in television program into education,let the student study the knowledge of chemistry in the television program,that may create an interesting learning environment for the learner,and is helpful in raising learner's study interest.
2016, 31(10): 98-104
doi: 10.3866/PKU.DXHX201602011
Abstract:
Suzuki-Miyaura reaction is a coupling process of aryl boric acid (boron ester) and aryl halide that catalyzed by palladium (0).The reaction shows well tolerance for various functional groups and is wildly applied in syntheses of natural products and organic materials.Recently,colleges abroad tried to introduce this reaction into the undergraduate organic lab.This paper collected the literatures in Journal of Chemical Education about the Suzuki-Miyaura reaction since 2000 and gave an overview.
Suzuki-Miyaura reaction is a coupling process of aryl boric acid (boron ester) and aryl halide that catalyzed by palladium (0).The reaction shows well tolerance for various functional groups and is wildly applied in syntheses of natural products and organic materials.Recently,colleges abroad tried to introduce this reaction into the undergraduate organic lab.This paper collected the literatures in Journal of Chemical Education about the Suzuki-Miyaura reaction since 2000 and gave an overview.
2016, 31(10): 105-105
doi: 10.3866/PKU.DXHX201609001
Abstract:
