• Lunin Valery Vasilievich(Chairman) - Professor, Dean of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, Academician of the Russian Academy of Sciences
• Arkhangelskaya Olga Valentinovna ( Deputy Chairman) - Associate Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of chemical sciences
• Eremin Vadim Vladimirovich
• Tyulkov Igor Alexandrovich- Associate Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of pedagogical sciences
• Terenin Vladimir Ilyich- Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, Doctor of Chemical Sciences
• Zhirov Alexander Ivanovich
• Lebedeva Olga Konstantinovna- Associate Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of chemical sciences
• Reshetova Marina Dmitrievna- Senior Researcher, Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of chemical sciences
• Trushkov Igor Viktorovich- Associate Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of chemical sciences
• Bacheva Anna Vladimirovna- Associate Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of chemical sciences
• Gladilin Alexander Kirillovich- Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, Doctor of Chemical Sciences
• Emelyanov Vyacheslav Alekseevich- Senior Researcher, Deputy Dean of the Faculty of Chemistry, Novosibirsk State University, Candidate of Chemical Sciences
• Zlotnikov Eduard Grigorievich- Associate Professor of the Faculty of Chemistry of the Russian State Pedagogical University. A.I. Herzen, Candidate of Chemical Sciences
• Kosmynin Vasily Vasilievich- Associate Professor of the Faculty of Chemistry, Belgorod State University, Candidate of Chemical Sciences
• Leenson Ilya Abramovich- Associate Professor of the Faculty of Chemistry, Moscow State University. M.V. Lomonosov, candidate of chemical sciences
• Medvedev Yury Nikolaevich- Associate Professor, Deputy Dean of the Faculty of Chemistry, Moscow Pedagogical State University, Candidate of Chemical Sciences
• Reutov Vladimir Alekseevich- Professor, Head of the Department of Chemical Technology, Faculty of Chemistry, Far Eastern State University, Doctor of Chemical Sciences
• Samorukova Olga Leonidovna- Associate Professor of the Russian Chemical-Technological University. DI. Mendeleev, candidate of chemical sciences (as agreed)

I.A.tyulkov, O.V. Arkhangelskaya M.V. Pavlova

Chemistry Olympiad Preparation System

Lectures 5–8

Pedagogical University "First of September"

Igor Alexandrovich Tyulkov, Olga Valentinovna Arkhangelskaya, Maria Vyacheslavovna Pavlova

Materials of the course "System of preparation for Olympiads in Chemistry": lectures 5–8. - M .: Pedagogical University "First of September", 2009. - 96 p.

Teaching aid

Editor O.G. Blokhin

Computer layout D.V. Kardanovsky

Signed for publication on 17.06.2009.

Format 60×90/16. "Times New Roman" typeface.

Offset printing. Pech. l. 6.0 Circulation 200 copies. Order No.

Pedagogical University "First of September", st. Kyiv, 24, Moscow, 121165 http://edu.1september.ru

I.A. Tyulkov, 2008 O.V. Arkhangelskaya, 2008M.V. Pavlova, 2008

Pedagogical University "First of September", 2008

Lecture No. 1. The main goals and objectives of the Olympiad movement in the context of modern education in Russia. History of chemical

1 whom the Olympiad movement in Russia. The system of chemical olympiads and creative competitions in Russia. The role of chemical Olympiads in education and science.

Lecture No. 2. Methods of preparing and holding Olympiads at various levels. Organization of Chemistry Olympiads: from pro-

1 stogo to complex. Preparatory, main and final stages of organizing Olympiads. The system of actors of the Olympiad, their role.(Tyulkov I.A., Arkhangelskaya O.V.)

Lecture No. 3. The conceptual basis of the content of the Olympiad tasks

dachas. Approximate program for the content of various stages of Chemistry Olympiads: rigid boundaries or guidelines for preparation?

1 Classification of Olympiad problems. Tasks of Chemistry Olympiads: from stage to stage, from tourism.(Tyulkov I.A., Arkhangelskaya O.V.)

Test No. 1

Lecture No. 4

1 conversions. Classification of problems with transformation schemes. Tactics and strategy for solving Olympiad problems with "chain-

kami." (Tyulkov I.A., Arkhangelskaya O.V., Pavlova M.V.)

Lecture No. 5. Methods for solving problems in physical chemistry (1). Tasks

2 in thermochemistry. Tasks using the concepts of "entropy" and "energy

gia Gibbs". (Tyulkov I.A., Arkhangelskaya O.V., Pavlova M.V.)

Lecture No. 6. Methods for solving problems in physical chemistry (2).

Tasks on chemical equilibrium. Tasks on kinetics. (Tyulkov

2 I.A., Arkhangelskaya O.V., Pavlova M.V.)

Test No. 2

Lecture No. 7. Methodological approaches to the implementation of experiments

2 tasks. Classification of tasks of the experimental round. The practical skills necessary for the successful implementation of the experiment

mental tasks.(Tyulkov I.A., Arkhangelskaya O.V., Pavlova M.V.)

Lecture No. 8. Methodological principles of preparing schoolchildren for kolympiads. The use of modern pedagogical technologies in the preparation of kolympiads of various levels. Tactics and strategy for preparing and participating in olympiads. Organizational

2 methodical work mentor teacher. Methodical approaches to compiling olympiad tasks. Olympiads as a means of improving the qualifications of teachers-mentors. The role of Internet communication and mass media in the exchange of pedagogical experience. (Tyulkov I.A., Arkhangelskaya O.V., Pavlova M.V.)

Final work

Lecture #5

Methods for solving problems in physical chemistry(1)

Problems in thermochemistry

Any chemical reaction is accompanied by the absorption or release of energy (ΔЕ), this energy is commonly called the “heat effect of the reaction.” In a simplified form, one can imagine that the change in energy occurs due to the fact that during the chemical reaction, chemical bonds in the starting substances are broken (while energy is absorbed) and new chemical bonds are formed in the reaction products (while energy is released into the external environment). If the energy spent on breaking chemical bonds is greater than the energy released during the formation of new chemical bonds, the reaction proceeds with the absorption of energy. In the opposite case, with the release of energy.

The energy that accompanies chemical reactions can take various forms.

	Table 1
Types of released energy
chemical equation	Type of energy
NaOH (solution) + HCl (solution) =	thermal
NaCl (solution) + H2 O (l.)
Mg (solid) + 1 / 2O2 (g) \u003d MgO (solid)	Thermal and light
	Thermal and mechanical (produc-
	there is a decrease in the volume of reaction
NH3 (g) + HCl (g) = NH4 Cl (solid)	onnoysystem: from two gases -
	ny substances it turns out solid
	substance), environment
	doing work on the system

	chemical equation		Type of energy
			Thermal and mechanical (origin-
	Zn (solid) + 2HCl (solution) =		there is an increase in the volume of the system
			we, because gaseous
	ZnCl2 (solution) + H2 (g)
			substance), the system performs
			work on the environment
	Zn (solid) + Cu (solution) =		Electrical and thermal
	Zn (solution) + Cu(solid)

A reaction accompanied by the release of heat into the environment is called exothermic reaction. A reaction accompanied by the absorption of heat from the environment is called endothermic reaction.

The joule (J) is the basic unit for measuring heat in the International System of Units (SI). In old works, the calorie equal to 4.184 J is also found as a unit of measurement. At present, it is preserved as an off-system unit for comparing the results of modern works with experimental and reference data accumulated over hundreds of years.

The equation of a chemical reaction, in which the energy (usually thermal) effect of a reaction to a certain amount of a substance (as well as other factors on which this effect depends) is indicated, is called thermochemical reaction equation.

The science that studies the thermal effects of chemical reactions is called thermochemistry. The thermal effect of a chemical reaction is the energy released or absorbed during a chemical reaction.

in the form of heat (or mechanical work, which is also converted

in ultimately into thermal energy).

The thermal effect of the reaction, measured at constant pressure, is denoted as Q p , ( thermochemical designation) or H p-tion (the enthalpy of reaction - thermodynamic designation).

Q p \u003d - H p-tion.

	Lecture #5
The heat of reaction is equal to the enthalpy of this reaction, taken inversely
In what follows, we will use the notation Q instead of
then Q p , because only reactions occurring at
	constant pressure
	Exothermic
	reactions going on
	release of heat from
	systems in the environment
	environment (Fig. 1):
	Q > 0, H p-tion< 0.
	For example, grief-
	coal mining:
Rice. 1. The enthalpy of the system decreases,	C + O2 = CO2.
energy is released from the system into the environment	Endothermic
ΔH p-tion< 0
	reactions going on
	heat absorption
	system iso-environment
	environment (Fig. 2):
	Q< 0, H р-ции > 0.

Endothermic reactions include some decomposition reactions, for example:

Rice. 2. The enthalpy of the system increases, the system takes energy from the external environment, ΔH p-tion > 0

CaCO3 = CaO + CO2,

all reactions of interaction of nitrogen with oxygen, etc.

Methods for solving problems in physical chemistry (1)

Factors affecting the thermal effect of a chemical reaction:

1) the nature of the reactants;

2) the amount of reactants;

3) aggregate states of substances;

4) allotropic or polymorphic modifications of substances. The first two factors, in our opinion, are obvious.

states and allotropic modifications are illustrated by the following examples.

1) Obtaining compounds with the formula H from simple substances 2 O

in different aggregate states (Fig. 3).

Rice. 3. Energy diagram for obtaining water from simple substances:

∆H1 is the enthalpy of the reaction of water formation in the gaseous state; ∆H2 is the enthalpy of the reaction of formation of liquid water; ∆H3 is the enthalpy of the reaction of formation of water in the crystalline state; ∆H4 is the enthalpy of evaporation (condensation) of water; ∆H5 is the enthalpy of melting (crystallization)

tion) water; ∆Н6 – enthalpy of ice sublimation

			Lecture #5
Thermochemical equations:
	(g) + 1/2O2	(g) = H2 O (g) + 242 kJ;
	(g) + 1/2O2	(g.) = H2 O (l.) + 286 kJ;
	(g) + 1/2O2	(g.) \u003d H2 O (tv.) + 292 kJ.

The given data clearly show the influence of the state of aggregation on the thermal effect of the reaction:

Q1< Q 2 < Q 3.

2) The combustion of graphite and diamond, as a result of which one

and the same substance is carbon dioxide (Fig. 4).

Rice. 4. Energy diagram of combustion of graphite and diamond:

∆H1 is the enthalpy of formation of CO 2 (g), numerically equal to the enthalpy of combustion of graphite; ∆H2 is the enthalpy of combustion of diamond (not equal to the enthalpy of formation of CO 2 (g), since the standard state of carbon is not diamond, but graphite); ∆H3 is the enthalpy

phase transitiongraphite-diamond

Thermochemical equations:

C (alm.) + O2 (g.) = CO2 (g.) + 395 kJ;

C (gr.) + O2 (g.) = СO2 (g.) + 393 kJ.

Methods for solving problems in physical chemistry (1)

remember again that –∆ H p-tions = Q.

The standard enthalpy of formation of a substance (∆H arr) is the enthalpy of the reaction of formation of 1 mol of a substance from simple substances in the standard state under standard conditions (pressure 101 325 Pa, temperature 298 K). All substances are in the most stable state under standard conditions. For example, for oxygen, hydrogen, nitrogen such a stable state is gaseous, for carbon it is graphite, for sulfur it is a rhombic modification, for water it is a liquid state, for most salts it is a solid crystalline state, etc.

The enthalpy of formation of a simple substance in the standard state under standard conditions is zero.

If ∆ H arr of a substance is less than zero, this means that energy was released during the formation of this substance. Therefore, energy must be expended to destroy this compound. The more energy released during the formation of a substance, the more thermodynamically stable it is, as a rule.

The enthalpies of formation of many substances are given in special reference books.

Standard enthalpy of combustion of a substance is the enthalpy of the combustion reaction (∆H burn ) 1 mol of substance in gaseous oxygen at p (O 2 ) = 1 bar. The calorific value of a hydrocarbon, unless otherwise noted, corresponds to the oxidation of carbon to CO 2 (g.), hydrogen to H 2 Oh (f.). For other substances, it is customary to indicate the resulting products in each case. For example, the following thermochemical equations can be written:

CH3 OH (l.) + 1.5O2 (g.) \u003d CO2 (g.) + 2H2 O (l.) + 726 kJ;

C2 H5 Cl (g.) + 3O2 (g.) = 2CO2 (g.) + HCl (g.) +

2H2 O (l.) + 685 kJ;

FeS(solid) + 1.75O2 (g) = 0.5Fe2 O3 (solid) + SO2 (g) + 828 kJ;

CH3 NH2 (g.) + 2.25O2 (g.) = CO2 (g.) + 2.5H2 O (l.) + + 0.5N2 (g.) + 1768.5 kJ.

	Lecture #5

We emphasize once again that the enthalpies of combustion of methanol, chloroethane, iron(II) sulfide and methylamine are –726, –685, –828, –1768.5 kJ, respectively.

Usually, schoolchildren and even students learn with great difficulty the definitions of the enthalpies of formation and combustion of substances. To remove this barrier, it is useful to refer to the algorithm for constructing a

leniya. For example, when defining standard enthalpy of formation of a substance answer the following leading questions.

1) Enthalpy of what reaction?

(Chemical formation reaction.)

2) How much of the substance should be formed during this reaction?

3) What is this substance made of?

(From simple substances.)

4) In what state should the starting materials be taken?

(In standard states.)

5) Under what conditions should the reaction proceed?

(Under standard conditions.)

Consistent answers to the questions posed add up to a definition. The standard enthalpy of formation of a substance (∆ H arr) is the enthalpy of the chemical reaction of formation of 1 mol of a substance from simple substances taken in standard states under standard conditions. Similarly, the definitions of the enthalpy of the reactions of combustion of a substance, phase or allotropic transition, formation of a chemical bond, etc., are “built”.

Choose the reaction equation, the enthalpy of which will be equal to the standard enthalpy of formation of copper(II) sulfite (CuSO3):

a) Cu (at.) + S (at.) + 3O (at.) \u003d CuSO3 (solid); b) CuO (solid) + SO2 (g) = CuSO3 (solid);

c) Cu (solid) + S (rhombus) + 1.5O2 (g) = CuSO3 (solid); d) 2Cu (solid) + 2S (rhombus) + 3O2 (g) \u003d 2CuSO3 (solid).

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Tyulkov Igor Alexandrovich. Studying a course of general chemistry based on chemical thermodynamics as a system-forming factor: Dis. ... cand. ped. Sciences: 13.00.02: Moscow, 2001 177 p. RSL OD, 61:02-13/833-6

Introduction

Chapter 1. The course of general chemistry in the system of chemical education of higher and secondary schools.

1.1 Analysis of the content of general chemistry courses studied at universities and secondary schools 8

1.2. Chemical thermodynamics in the course of general chemistry 19

1.3. Methods of teaching general chemistry in universities 24

1.4. Seminar in the system of teaching students of general chemistry. Methodological approaches to conducting seminars in general chemistry at the university and their justification 29

1.5. The role of the computer in the educational process at the seminar in teaching general chemistry 34

1.6. Control and diagnostics of students' learning outcomes at seminars...39 Chapter 2. Formation of the concept of teaching students of general chemistry at seminars based on chemical thermodynamics as a system-forming factor 46

2.1. 46

2.2. Construction of seminars in general chemistry based on chemical thermodynamics as a system-forming factor 49

Chapter 3

3.1 Conducting a seminar on chemical thermodynamics using various methods 57

3.2 Methodology for evaluating the effectiveness of a seminar on chemical thermodynamics

3.3 Comparing the results of the three training options 65

3.5. Study of the methodology for conducting seminars in general chemistry based on chemical thermodynamics as a system-forming factor 69

3.6. The results of the study of the effectiveness of conducting seminars in general chemistry based on chemical thermodynamics as a system-forming factor and discussion of the results 73

Literature 94

Applications 108

Appendix 1. The content of chemical thermodynamics in programs in general chemistry Appendix 2. Interdisciplinary relationships identified in the analysis of programs in general chemistry 111

Appendix 3. Chemical thermodynamics test 112

Appendix 4. Seminar Plans 144

Annex 5. Results of fulfilling the tasks of the ascertaining research in 1998/1999

and 1999/2000 academic years 148

Annex 6. Examples of colloquium assignments and results of colloquia assignments by students of the Faculty of Geography, Faculty of Geology and the Faculty of Fundamental Medicine of Moscow State University 153

Appendix 7. The results of the assignments of the final work by students of the geographical, geological faculties and the faculty of fundamental medicine of Moscow State University 170

Introduction to work

Higher education is aimed at training specialists of a wide profile, capable of constant creative search and acquisition of new knowledge. The main objectives of teaching general chemistry are:

Creation of a solid foundation of theoretical knowledge in general chemistry necessary for the successful study of other chemical disciplines provided for by the curriculum of the relevant specializations (physical, analytical, colloidal, organic chemistry, etc.), as well as a number of academic disciplines related to chemistry (hydrology, meteorology, crystallography, ecology, biochemistry, biophysics, etc.)

Formation of students' methods of scientific thinking to replenish and apply knowledge in solving research problems.

In the current practice of teaching, the course of seminars in general chemistry is built linearly. In a similarly structured course, individual topics form a continuous sequence of topics (chemical thermodynamics, kinetics, equilibria in solutions of non-electrolytes and electrolytes, etc.), which are worked out once during the training. With such a structure of presentation, knowledge not properly acquired by students in previous seminars cannot be fully used in the study of subsequent topics, which means that the effectiveness of training decreases. In the study of each subsequent topic, students should actively draw on previously acquired knowledge. However, this does not happen for the reason described above, and also because of the low motivation of students to study the course of general chemistry. A negative role is also played by the low connectedness of the topics of the seminars. Often the sequence of topics is historically established or arbitrarily chosen by the university. Teachers often do not explain to students the goals of studying chemistry in the natural science departments and do not show the prospects for studying chemistry. Interdisciplinary connections between chemistry and subjects studied by students in their faculties or streams are not revealed. As a result, students' knowledge of chemistry acquires a formal character. This is manifested in the fact that:

Knowledge is formed by memorizing material without understanding its application.
niya.

There is no correlation of the acquired knowledge with previous ideas and
concepts (the so-called isolation of knowledge is observed).

Thus, the main problem research lies in the formality of knowledge in general chemistry among students of non-chemical natural science specialties of universities. The traditional construction of a course of seminars in general chemistry and the methods used in teaching do not contribute to the formation of conscious and systematic knowledge of general chemistry for further study of chemistry at a university.

4 The solution to this problem lies in the development of an approach to teaching chemistry, based

which is to strengthen the relationships between the various sections of the course. This is possible when using the fundamental section of the course of general chemistry as a backbone factor. Under system-forming factor we understand the system of theories, laws and concepts that link the sections into a single course.

Thermodynamics is one of the fundamental sections of the general chemistry course at the university. Often the training of students of natural science non-chemical specialties begins with this section. Energy changes are the inner essence of chemical processes, allowing a deeper understanding of the pattern of their course.

Concerning relevant It is proposed to develop a methodology for conducting seminars in general chemistry based on chemical thermodynamics as a system-forming factor.

The relevance is due to:

the need to eliminate the formalism of knowledge in general chemistry among students of natural science specialties of universities;

conditions that have matured in higher education for building a course of general chemistry based on a system-forming factor;

poor development in the methodology of teaching chemistry of the task of constructing a course of seminars in general chemistry based on a system-forming factor.

Main idea of ​​work is to rethink the content of the course of seminars in general chemistry and to develop a new methodological approach to teaching general chemistry based on chemical thermodynamics as a system-forming factor.

Object of study: the process of teaching general chemistry at the natural science faculties of universities.

Subject of study: the structure of the course of seminars in general chemistry based on thermodynamics as a system-forming factor.

Target of this study is to develop the construction of the content and organization of teaching general chemistry to students of natural science non-chemical specialties of universities based on chemical thermodynamics, as a system-forming factor.

In this work, it was put forward hypothesis, that the formation of a solid foundation of knowledge in chemical thermodynamics, the construction of a system of seminars in general chemistry based on chemical thermodynamics as a system-forming factor, the identification of the relationship of the section of chemical thermodynamics with the rest of the sections of this course and with other natural science disciplines, will allow students to realize general chemistry as an integral system directed on the:

* obtaining systematic and conscious knowledge of general chemistry;

formation of the foundations of scientific thinking.

The purpose and hypothesis determined the following research objectives:

I. Conduct an ascertaining study:

a) analyze the pedagogical, methodological and scientific literature on the topic of
following;

b) analyze the curricula and curricula used in different
faculties;

c) identify the initial level of knowledge of students.

II. Develop a methodically sound concept for building a course of seminars
classes on general chemistry based on chemical thermodynamics as a backbone faculty
Torah.

III. Develop a methodological approach to conducting seminars on the course of
cabbage chemistry:

a) to develop a system of seminars in general chemistry, built on the basis of chemical
thermodynamics as a system-forming factor;

b) develop a methodology for holding a seminar on chemical thermodynamics.

IV. Check the effectiveness of the proposed methodological approach.
Reliability and validity scientific provisions and conclusions provided:

reliance on the conclusions of psychological science, general and particular didactics;

using a variety of research methods adequate to the tasks.

The following research methods were used in the work: analysis of psychological and pedagogical literature on the research problem, methods of ascertaining research and formative experiment, systematic approach, methods of pedagogical research using specially designed tasks for diagnosing formed knowledge, testing, qualitative and quantitative analysis of students' answers, mathematical processing research results and their methodological interpretation.

The study was carried out in several stages (1996 - 2000):

An ascertaining study, which made it possible to theoretically study the state of the problem under study, determine the goals, subject, tasks, research hypothesis.

Theoretical stage for the development of the concept of building a course of seminars in general chemistry based on chemical thermodynamics as a backbone factor.

An experimental stage for organizing and conducting a pedagogical experiment in order to test the effectiveness of a seminar on chemical thermodynamics. Analysis and interpretation of the results of this stage of the study.

An experimental stage for organizing and conducting a pedagogical experiment in order to test the put forward working hypothesis.

The final stage is the analysis and interpretation of the results of the pedagogical experiment, the generalization of the results of the entire study, the formation of scientific conclusions.

Scientific novelty:

A new system of teaching students at seminars in general chemistry has been created, which is based on chemical thermodynamics as a system-forming factor.

A set of didactic materials has been created for the methodological support of the proposed course (plans of seminars, a testing computer program on chemical thermodynamics, a set of tasks for introductory, midterm and final control).

Theoretical significance of the work consists in creating the methodological foundations of a course of seminars in general chemistry, built on the basis of chemical thermodynamics as a system-forming factor. The necessity of building a course based on this approach is substantiated.

Practical significance of the work: The proposed methodological approach to the creation and use of a system of seminars in general chemistry makes it possible to apply it when teaching general chemistry at a university.

Reliability of results due to the choice of adequate modern research methods, the positive values ​​of the performance indicators of the developed approach to teaching general chemistry.

Approbation and implementation of the results.

The results of the study were discussed at:

VIII International conference-exhibition "Information technologies in education", Moscow, 1998;

All-Russian scientific and methodological seminar at Moscow State Pedagogical University. V. I. Lenin, 1998

scientific conference "Lomonosov Readings-99", Section "Methodological problems of continuous education", subsection "Chemistry and Ecology", Moscow, 1999;

International scientific-practical conference "Improving the teaching of chemistry at school and university", Irkutsk, 1999

International Congress "Science and Education on the Threshold of the III Millennium". Minsk, 2000

7 XLVIII Herzen readings (All-Russian scientific-practical conference with international participation "Actual problems of modern chemical-pedagogical and chemical education"), St. Petersburg, 2001 meeting of the laboratory of chemistry IOSO RAO, 2001

meeting of the Department of Inorganic Chemistry and Methods of Teaching Chemistry, Moscow State Pedagogical University. V. I. Lenin, 2001

The results of the study are used in the practice of the Department of General Chemistry, Faculty of Chemistry, Lomonosov Moscow State University. M. V. Lomonosov.

The structure and scope of the dissertation. The work consists of an introduction, three chapters, conclusions, a list of references and applications. Its content is set out on 107 pages. The full text of the dissertation consists of 177 pages. The work includes 55 figures, 17 tables, 3 schemes. The list of used literature contains 229 titles, 23 of them are in foreign languages. The appendices contain the content of the section "Chemical thermodynamics" in various programs in general chemistry; interdisciplinary connections revealed in the analysis of programs in general chemistry; full text of the test on chemical thermodynamics, developed by the author; the results of students' fulfillment of tasks of the control section of students' knowledge; options for tasks of colloquia and the results of their implementation; the results of completing the assignments of the final work.

The following provisions are put forward for defense:

The use of chemical thermodynamics as a system-forming factor requires the restructuring of the content of seminars and their sequence in the course of general chemistry.

The construction of seminars on the basis of chemical thermodynamics as a backbone factor contributes to the formation of the basics of scientific thinking in students, as well as systemic and conscious knowledge of general chemistry.

Analysis of the content of general chemistry courses studied at universities and secondary schools

Most university textbooks are focused on the system of concepts about matter. In these textbooks, the sections “structure of the atom”, “chemical bond”, “periodic law of D. I. Mendeleev” are taken out at the beginning.

It should be noted that the sequence of presentation of even these three sections of general chemistry is different for different authors. So in textbooks, the order of presentation is as follows: the structure of the atom is the periodic law and the periodic system of elements is the chemical bond. In a number of other manuals, this sequence is different: the periodic law and the periodic system of elements - the structure of the atom - the chemical bond.

An analysis of the construction of courses focused on the system of concepts of matter shows that a significant number of courses have in common the construction in the following sequence: the structure of the atom - the chemical bond - the description of the properties of chemical elements and their compounds. Such a construction, apparently, is united by an idea that was clearly expressed by Ya. A. Ugai: “The idea of ​​the relationship between the chemical structure of a substance ... and its properties runs like a red thread through the entire course of inorganic chemistry. In this regard, special attention is drawn to the theory of the chemical structure of A. M. Butlerov in its modern interpretation, which is essentially a general chemical theory... Ultimately, the most important task of chemistry... was and remains to identify the relationship between the chemical structure of a substance, on the one hand side and its properties on the other.

It should be noted that O. M. Poltorak and Yu. A. Pentin in their works reasonably show that the search for an unambiguous relationship between the structure of molecules and the chemical properties of a substance is doomed to failure in advance. Without knowledge of the basics of chemical thermodynamics and kinetics, it is impossible to draw conclusions about the possibility of a chemical process, its depth and speed. G.P. Luchinsky also confirms this idea: “The current level of development of chemistry requires a presentation of the course of science from the standpoint of the doctrine of the structure of matter and thermodynamics.”

The second type of textbooks is focused on the system of concepts of a chemical reaction, and there are much fewer of them than textbooks of the first type. In these textbooks, the study of the laws of the course of chemical reactions is brought to the fore, i.e. thermodynamic and kinetic aspects.

In different textbooks, the sequence of presentation of the fundamentals of chemical thermodynamics and kinetics is different. In the textbooks, the authors put chemical thermodynamics first and kinetics second. Other manuals and textbooks [11, 49, 183, 184, 222, 229] suggest the order: kinetics - thermodynamics.

In addition, as noted above, the very position of these topics in the course also differs significantly. For example, in manuals, the topics mentioned are presented after the structure of the atom, the periodic system, and the concept of a chemical bond. In textbooks, thermodynamics and kinetics are considered much later; they actually precede the description of the chemical properties of elements and compounds.

The order of presentation of topics is practically none of the authors, with the exception of the OS. Zaitsev, B.V. Nekrasov, G.I. Novikov and a number of others, is not substantiated, and in existing textbooks there is a wide variety of the sequence of their introduction.

G. I. Novikov proposes the construction of a textbook based on "the sequence of steps of the theoretical principles of chemistry: stoichiometry, thermochemistry,

ergochemistry (chemical equilibrium and the foundations of chemical thermodynamics), chronochemistry (the foundations of kinetics), the beginning of the study of the structure of matter (the structure of the atom, molecules, liquids, crystals and compounds with non-valent bonds).

B.V. Nekrasov builds the content of the textbook on the basis of the Periodic Law of D. I. Mendeleev, The author notes that “... you need to do everything possible not just to “state” the course, but to develop it logically, which is especially important ... when considering theoretical questions ... The construction itself must first of all ensure the possibility of its logical deployment.

A special place is occupied by the textbook "Chemistry. A modern short course" by O. S. Zaitsev. The book is designed largely for independent study of the subject, "the purpose of the book is to develop students' chemical thinking so that the future specialist can not only independently solve various chemical problems, but also transfer the general methods of scientific work to work in their specialty" . The author points out that consideration of the state of matter and chemical reactions is given on the basis of the fundamental theories of modern chemical science and their interrelations. The logical basis of the mentioned course is a system of knowledge about four fundamental doctrines: about the direction of chemical processes (chemical thermodynamics) and their speed (kinetics), the theory of the structure of matter and the periodicity of changes in the properties of elements and their compounds

Selection of material on chemical thermodynamics for seminars on the course of general chemistry, built on the basis of chemical thermodynamics as a system-forming factor

Selection of material on chemical thermodynamics for seminars on the course of general chemistry, built on the basis of chemical thermodynamics as a system-forming factor

As shown above (1.1), when building a course in general chemistry, the most acceptable sequence of presentation of the material is the following: chemical thermodynamics (without chemical equilibrium) - "chemical kinetics + chemical equilibrium - # solutions, equilibrium in solutions - atomic structure - chemical bond - periodic law of D. I. Mendeleev. Chemical thermodynamics is a fundamental section of the general chemistry course, so the seminar on chemical thermodynamics is one of the first in various general chemistry courses. The knowledge formed at this seminar should be considered basic. They are the basis for further study of the course of general chemistry. Therefore, an urgent problem is the selection of the content of chemical thermodynamics, which is a backbone factor for the experimental course of seminars in general chemistry.

The selection of material on chemical thermodynamics for seminars in general chemistry was carried out according to the following principles:

Compliance of the material with the modern level of science;

The possibility of using the material by students in future scientific activities;

The relationship between the material of the seminar and the material presented in textbooks and manuals recommended to students;

Using knowledge from other disciplines within the scope studied so far;

Limitation of the material by the curriculum and the time of studying the course of general chemistry;

The presence of a connection between the material of the seminars and other sections of the course of general chemistry;

The presence of interdisciplinary links with other disciplines.

Based on the analysis of the content of the section of chemical thermodynamics in programs in general chemistry and literature (in 1.1 and 1.2), the section of chemical thermodynamics is represented by a system consisting of five components arranged in the following sequence (see Scheme I).

As noted in 1.2, the section "Chemical thermodynamics" has connections with almost all sections of the general chemistry course, such as:

The rate of a chemical reaction. Mechanisms of chemical reactions. Catalysis;

Solutions. Equilibria in solutions;

Redox processes;

Fundamentals of electrochemistry;

Chemical bond;

Complex compounds;

Dispersed systems;

Periodic law and the periodic system of chemical elements. An analysis of programs in general chemistry and other natural science disciplines revealed that the section "Chemical Thermodynamics" has many interdisciplinary connections (with biology, geology, medicine, ecology and other disciplines studied by students of natural sciences) (see Appendix 2, Table 12). It should be noted that in programs in general chemistry, interdisciplinary integration is not fully revealed.

In the formation of systematic scientific knowledge, an important role is played not only by a reasonably selected subject material, but also by the sequence of its study, which is mainly determined by the following three didactic principles: consistency, accessibility and scientific character.

Conducting a seminar on chemical thermodynamics using various methods

In order for students to use knowledge of chemical thermodynamics, it is necessary to lay down a complete and deep knowledge of the basics of chemical thermodynamics in the first seminars. Therefore, the effectiveness of holding a seminar on chemical thermodynamics was first investigated.

In the 1996/97 academic year, a study was made of the effectiveness of holding a seminar on chemical thermodynamics.

We compared the methods of conducting a seminar on thermodynamics. The experiment consisted in the fact that three groups of students (13 people each) were held three types of seminars: a conventional seminar (the seminar is conducted as it is implemented on the stream) a computer seminar (individual work of students with a computer training program) a combined seminar (combination of individual work students with a computer-based tutorial, discussing the most important issues and explaining difficult concepts)

The initial level of students' knowledge was tested at the first seminar (stating research). They were asked to complete the following task: The reaction equation for the combustion of graphite in oxygen was given

1) What is the reaction; exo or endothermic?

2) Calculate the mass of graphite required to obtain 1179.3 kJ of heat. Quantitative data on the implementation of the proposed task are shown in fig. 3. The percentage of success in completing tasks is plotted along the y-axis, i.e. % of correctly completed tasks from the total number of tasks, along the abscissa - the number of the question of the task, which checks the initial level of students' knowledge. Based on the data in Fig. 4, we can say that only 15% of students in all groups can characterize the reaction by the thermal effect and can make thermochemical calculations.

It can be concluded that the level of knowledge of students in chemical thermodynamics before training is almost the same. It should be noted that by the time they start studying general chemistry, most students are not able to carry out elementary thermochemical calculations and characterize reactions in terms of energy effects.

In the programs and curricula in general chemistry, the seminar "Fundamentals of Chemical Thermodynamics" is one of the first. It lays down thermodynamic knowledge, based on which students can calculate the values ​​of AH, AS, AG of chemical processes and evaluate the fundamental possibility of chemical processes occurring under given conditions.

The main goal of this seminar is to lay a solid foundation of knowledge in chemical thermodynamics, since a successful study of a general chemistry course is impossible without resolving the basic issues of chemical thermodynamics:

What is the thermal effect of the process?

Is it possible for the process to proceed spontaneously, and under what conditions?

What is the depth of the chemical process?

The same educational material was selected for the seminars, including the basic laws and concepts of chemical thermodynamics.

The seminar in the generally accepted version was held according to the methodology used by most university professors to explain the basic concepts of thermodynamics. In this method, most of the time was devoted to explaining the educational material by the teacher and teaching students the skills to solve typical problems. At the beginning of the lesson, frontal work is carried out, but updating the knowledge gained by students in the previous lecture on chemical thermodynamics. Then the teacher introduces students to the concepts: chemical systems, the thermal effect of the reaction, processes with the release and absorption of heat, standard and normal conditions, the enthalpy of various processes: the formation of substances, the formation of chemical bonds, phase transition and combustion of substances. Particular attention is paid to solving problems on the Hess law and its consequences. Further, students get acquainted with the concept of entropy, the second and third laws of thermodynamics, free energy and Gibbs energy, a criterion for the spontaneous occurrence of chemical processes. Students solve problems to find the value of entropy and Gibbs free energy and draw conclusions about the fundamental possibility of spontaneous chemical processes.

Computer training programs developed by the team of the Department of General Chemistry of the Faculty of Chemistry of Moscow State University were used to conduct a seminar on computer methods. They are a universal invariant tool that combines the possibility of using a dialogue, a data bank, textual information, calculations and test control. The programs alternate sheet material with a phased control of the student's knowledge. They are built in a dialogue mode, which allows for effective feedback in training and timely correction of the students' chemical knowledge. The student independently works with the programs, therefore, he controls the process of his own learning and determines the pace of mastering the material that is convenient for him.