Collective thinking. Groupthink: features and consequences for a person

Larina Elena Alexandrovna

Municipal educational institution secondary educational school No. 45 of the Traktorozavodsky district of Volgograd

Virtual experiment in chemistry class.

The development of cognitive interests of students in the learning process has great importance for any subject. The study of chemistry has its own characteristics that it is important for the teacher to keep in mind. First of all, this concerns the use of an educational chemical experiment, which is widely used at school in various forms. To successfully teach chemistry, the teacher needs to master the school chemical experiment, as a result of which students acquire the necessary knowledge and skills. In the absence of a chemical experiment in chemistry lessons, students' knowledge can acquire a formal shade - interest in the subject drops sharply.

Chemistry is interesting, but complex science. Of all the natural sciences, chemistry requires the most logical thinking, and it is often difficult for students to correlate electronic circuits with what are real atoms or molecules, the equations of chemical reactions with real chemical processes.

A chemical experiment is a specific method of teaching chemistry, since it distinguishes the process of teaching chemistry from teaching other subjects of the natural science cycle. A number of methodologists-chemists consider the experiment as a specific method and means of teaching chemistry. That is why the use of a chemical experiment in teaching is one of the most developed problems in the methodology of teaching chemistry.Chemical experiments make it easier to remember the properties of substances, or to understand the essence of ongoing processes. Viewing experiences leaves a sense of presence and gives complete picture what is happening.

In schools, a rather tense situation has now developed both with the availability of reagents and with the problems of their safe use, as the list of substances prohibited for use and storage in the school chemistry room and school chemistry laboratory is constantly growing. AT last years there was another problem. Pupils come to school with various allergic diseases, very susceptible to various smells. But in the process of explaining new material, it is necessary to carry out those experiments that cannot be carried out “live”. However, about these reactions in question in a school textbook, their descriptions are given, equations are given, for example: the interaction of mercury with sulfur, the decomposition of nitrates, the interaction of metals with chlorine and bromine. In all these cases, a virtual experiment is the only opportunity to get acquainted with these reactions with your own eyes, to "materialize" in the minds of students what is sometimes impossible to see or even describe as a macro object. Therefore, in my practice, I began to use a virtual experiment when conducting chemistry lessons. This made it possible to virtually study the properties of any substances, including poisonous or explosive ones, to demonstrate chemical experiments that require reagents that are prohibited for use in school chemistry classrooms and laboratories.

What should be understood as a virtual chemical experiment, what types of it exist, where and how should a virtual chemical experiment be used?

A virtual chemical experiment is a type of educational chemical experiment in which a demonstration or simulation means chemical processes and phenomena is computer technology. The original definition of a virtual experiment was proposed by I.S. Ivanova. She believes that a virtual experiment is a computer simulation laboratory work, which assumes that the object of study and experimental setup are in an imaginary virtual space.

There are two main types of virtual chemistry experiment - virtual demonstrations and virtual laboratories.

Virtual demonstration - a computer program that reproduces dynamic images on a computer, creating visual effects that imitate the signs and conditions of chemical processes. Such a program does not allow user intervention in the algorithm that implements its work.

Virtual laboratory - a computer program that allows you to simulate a chemical process on a computer, change the conditions and parameters of its implementation. Such a program creates special opportunities for the implementation interactive learning. Virtual laboratories allow you to simulate a chemical experiment, which for some reason cannot be implemented in a school chemical laboratory (high cost of reagents, danger, time constraints). Computer models make it possible to obtain visual, memorable illustrations of complex or dangerous chemical experiments, to reproduce their subtle details that may escape during a real experiment. Computer simulation makes it possible to change the time scale, to vary the parameters and conditions of the experiment within a wide range, and also to simulate situations that are inaccessible in a real experiment.

Performing laboratory experiments and practical work using virtual laboratories, students independently explore chemical phenomena and patterns, in practice making sure of their reliability. Naturally, this Practical activities pupils cannot be carried out without the guiding word of the teacher. An important advantage of a virtual educational experiment is that students can return to it many times, which contributes to a stronger and deeper assimilation of the material.

In chemistry lessons, I use the electronic edition “Chemistry. Virtual laboratory for grades 8-11"

The disk clearly and colorfully demonstrates all the laboratory experiments of the basic and basic chemistry course. high school, all reference material is stored, there is a journal of laboratory work. The electronic edition "Virtual Laboratory for Grades 8-11" includes more than 150 chemical experiments that are carried out in a laboratory implemented on a monitor screen, equipped with the necessary reagents and laboratory equipment. great attention This is where safety precautions come into play. Using virtual reagents and equipment, you can conduct experiments in the same way as in a real laboratory. Students are given the opportunity to assemble various devices, installations from constituent elements, take measurements, enter their observations in the "Laboratory Journal", "take pictures" from the screen using a virtual camera, and draw up reaction equations.

The program controls every action of the student, leading him through all the stages necessary for the successful completion of the experience. When conducting a number of practical work, you can use video clips that allow you to see their experiment in a real laboratory. At the same time, students increase their cognitive interest, develop skills to work in compliance with safety regulations, the ability to observe, highlight the main thing and draw conclusions from observations.

Performing laboratory experiments on computer technology introduces certain features into the educational process.

It becomes possible to set up experiments not only in the process of presenting something new, but also when consolidating the material, generalizing knowledge, and solving experimental problems.

The organization of laboratory and practical work is improving. Students have the opportunity to individually perform experiments, which cannot but affect the development of independence, the formation of general laboratory, organizational and other practical skills.

When performing virtual experiments, there is a saving of training time, which is advisable to use for solving creative experimental problems, consolidating the material, or correctly understanding the essence of the reactions taking place.

The Virtual Lab Drive encourages students to experiment and enjoy their own discoveries.

Summarizing my experience with the use of a virtual experiment, I would like to note that a virtual experiment helps:

To form the ability to work with information, develop communication skills;

To assimilate the educational material as much as possible;

To form research skills, the ability to independently make optimal decisions.

Increases the volume of educational material, with significant time savings;

Improves the visibility of the presentation of educational material due to color, sound and movement;

The possibility of demonstrating those chemical experiments that are dangerous to the health of children;

Accelerates the pace of the lesson due to the emotional component.

Summarizing the above, I would like to wish my colleagues: “Do not be afraid, experiment and you will succeed, because only a teacher who is fluent in modern forms work, can arouse students' interest in their subject!

Chemistry is an interesting, but at the same time very complex experimental science. And its role in the school, as an experimental science, is to educate schoolchildren through various forms of work with natural substances and materials. Such experimental activity increases the motivation of students to study this subject. A chemical experiment is a specific teaching method, since it is it that distinguishes the process of teaching this science from teaching other subjects of the natural science cycle. The use of this form of work allows you to better remember the properties of the studied substances, as well as to find out the essence of the ongoing processes. But due to the lack of a laboratory, the lack of reagents and instruments, laboratory work is carried out very rarely. An alternative to these works is the use of a virtual laboratory. learning activities, during which students can transform their theoretical knowledge into practical ones, can be simulated using a virtual laboratory. The use of a virtual laboratory enables students to repeat any incorrectly performed experiment and study it in more detail. The virtual laboratory, in our opinion, has a number of advantages over traditional laboratory experiments.

1. Experiments using a virtual laboratory are safer (no direct contact with chemical reagents and products of their interaction, this is due to the fact that in recent times the number of students with various allergic diseases, which are very susceptible to various odors, is increasing).

2. Students can perform experiments that cannot be done in a real laboratory due to the lack of both chemicals and equipment to carry them out. Also, the use of DER allows you to virtually study the properties of any substances, including explosive poisonous ones, and demonstrate the chemical experiment, which requires reagents that are prohibited for use in the school chemical laboratory.

3. To perform many laboratory experiments, a large amount of time is required, and the use of the DER allows solving this problem.

4. One of the problems of the school is the disposal of used chemical reagents, so the virtual laboratory can solve this problem as well.

5. DERs allow each student to get involved in experimental activities.

Virtually conducted experiments allow students, in comparison with traditional method to study the process in more detail. DER can be used at different stages of the lessons:

- so, at the stage of explaining new material, as an illustration to the theory;

- at the stage of fixing the material - this is the use of both training tests and simulator programs;

- these resources allow students to carry out work on the modeling of molecules of inorganic and organic matter.

The use of a virtual laboratory helps the teacher in the formation of the most important chemical concepts, to understand the structure of the atom, molecules, chemical bonds.

The Virtual Lab encourages students to experiment and enjoy their own discoveries.

II. METHODOLOGY AND TECHNIQUE OF EDUCATIONAL CHEMICAL EXPERIMENT AT SCHOOL

2.1. Definition of the concept of educational experiment,

its classification and place in teaching chemistry

By the concept of "natural educational chemical experiment" we mean a means of teaching chemistry in the form of specially organized and conducted experiments with substances (reagents), included by the teacher in the educational process with the aim of cognizing, verifying or proving by students a chemical fact, phenomenon or law known to science, as well as for learning by students certain methods chemical science research.

The educational chemical experiment should be considered, first of all, as didactic tool to achieve the main learning objectives. With the help of a chemical experiment at school, you can teach children to observe phenomena, form concepts, study new educational material, consolidate and improve knowledge, form and improve practical skills, promote the development of interest in the subject, etc.

Unlike other means of visualization, an educational chemical experiment has a certain dynamics in time, that is, outward manifestation The process is constantly changing, as a result of the experiment, new substances are obtained that have properties that differ from the original substances, and with which new experiments can be carried out.

The peculiarities and diversity of chemical phenomena, and, consequently, of the educational chemical experiment make it possible to use it literally in all forms and at all stages of the educational process.

Usually, educational experiments performed in chemistry lessons are divided, depending on the subject of their conduct, into demonstration, laboratory experiments and practical work. A demonstration experiment is performed by a teacher or student for the public to see all students in the class; one conducts the experiment, the rest observe the process. Laboratory experiments are performed, as a rule, by all students in the class during the teacher's explanation. These experiments should be simple, short in time (2-3 minutes) and safe to carry out. Everything necessary for laboratory experiments should be prepared in advance on the tables of students. Practical work is an experiment on the study of a specific topic, performed by students under the guidance of a teacher throughout the lesson.

Basically this classification educational experiment is acceptable not only in relation to the lessons, but also for other forms of the educational process, such as: electives, workshops, elective courses, chemistry circles and other forms of extracurricular work, etc.

Depending on the number of reagents taken for the experiment and the size of the chemical glassware, the educational chemical experiment is divided into a macro-experiment and a micro-experiment, an experiment with a small number of reagents.

Microexperiment (micromethod) in the form of drop reactions and microscopic examination of sediments is widely used in analytical chemistry. It has a number of obvious advantages: it simplifies the course of analysis; the desired result is obtained faster, which is especially important in the work of clinical, sanitary and hygienic chemical and technological laboratories; less reagents are consumed; greater sensitivity is achieved, etc.

However, in school conditions, the use of a micro-experiment is in most cases inappropriate. First of all, this applies to demonstration experiments, which do not make sense in the form of drop reactions, since students will not be able to observe either the course of the reaction or its results. In addition, the use of a microexperiment requires the availability of a sufficient amount (for all students) of special equipment: micropipettes, plates for reactions, etc.

In our opinion, in practical classes and when conducting laboratory experiments, methods using small amounts of reagents should be used, and demonstration experiments should be carried out in the form of a macro experiment in order to ensure good visibility for all students.

Due to the fact that it is impossible to show some reactions at school, teachers in the study of chemistry resort to the so-called " thought experiment"- students represent in their minds, without observation in experience, certain processes that characterize the properties of substances, their production, etc., and in their minds predict the results to which this or that experience can lead. We propose to call this type experiment is not a "thought" but a "virtual experiment". Since we believe that the word "virtual" is more consonant with the era of computerization, that is, our time, this is modern. explanatory dictionaries Russian language and dictionaries foreign words the word "virtual" means "non-existent, but possible", "possible, which can appear under certain conditions".

According to the venue, it is possible to single out a school, home and field educational chemical experiment. Besides, special role entertaining experiments should be played at school. AT general view the classification of the educational chemical experiment can be presented in the form of a table.

It goes without saying that each type of educational chemical experiment has its own specific goals and performance features. Demonstration experiments in chemistry can be carried out in the form of natural processes or reactions; in the form of simulation experiments, when some substances are replaced by others for the purpose of greater safety, clarity and economy; in the form of a multimedia experiment, that is, showing experiments on TV, using a movie projector or a computer.

Classification of educational chemical experiment

LABORATORY EXPERIENCES

PRACTICAL WORKS OF STUDENTS

DEMONSTRATION-
EXPERIMENT

Goal: learning new material.

Purpose: consolidation and improvement of knowledge, formation and improvement of practical skills and abilities.

Purpose: to form the concepts of chemistry; learn to observe phenomena.

The action of indicators on acids and bases.

Color reactions to

Simulation experiments

An experiment carried out according to the instructions

Experimental problem

multimedia experiment

Obtaining diamonds from graphite.

Preparation and properties of phenol.

Replacing bromine water with iodine water.

Replacement of formaldehyde with glucose in the silver mirror reaction.

Get copper oxide in three ways and prove that this substance is a basic oxide.

Prove by experience that polyethylene contains carbon and hydrogen.

Obtaining carbon monoxide (IV) and experiments with it.

Obtaining ethyl ester of acetic acid.

EDUCATIONAL CHEMICAL EXPERIMENT

FIELD EXPERIMENT

VIRTUAL EXPERIMENT

HOMEEXPERIMENT

ENTERTAINING EXPERIENCES

Purpose: to make chemical experiments safer, cheaper and more visual; develop the thinking of students.

Purpose: to promote the development of interest in the subject and a more conscious assimilation of scientific knowledge.

Purpose: formation and development of students' interest in chemistry.

Decomposition of mercury oxide or Bertolet salt.

Synthesis of organic
connections.

Obtaining smokeless powder.

Eruption.

Spontaneous combustion
spirit lamps.

Express analysis of soil and water in the field.

Chemistry in
everyday life

Obtaining substances

The study of the properties of substances

Experiments with starch.

Sugar experiments.

Getting indicators.

Getting starch.

Properties of table salt, vinegar, soda, etc.

The main goal of demonstration experiments is the development of observation, the formation of new knowledge and concepts of chemistry. The key advantages of demonstration experiments are their visibility, the ability to promptly direct students' attention to the main link in the process, saving time and reagents. However, this type of experiment does not give students the opportunity to develop special skills.

Laboratory experiments are remarkable in that when they are included in the explanation of new material, students are personally convinced of the correctness of certain statements of the teacher and at the same time acquire some skills in a chemical experiment, develop observation skills. At the same time, preparation for conducting these experiments requires more time, reagents are spent, and the teacher has to pay more attention to ensuring safety in the classroom. The main purpose of laboratory experiments is to provide clarity when learning new material.

Practical work, being an important source of learning new material, also contributes to the formation and improvement of practical skills of students. The main problems in their implementation are the provision of all students with reagents, utensils and equipment, as well as the observance by all students of safety rules.

Performing laboratory experiments and practical work, students independently explore chemical phenomena and patterns, in practice making sure of their reliability. Naturally, this practical activity of students cannot be carried out without the guiding word of the teacher. It is necessary to ensure that when conducting experiments, students show a creative approach, that is, they would apply their knowledge in new conditions. An important advantage of these types of educational experiment is that students, in contrast to demonstration experiments, include almost all sense organs in the process of cognition, which contributes to a stronger and deeper assimilation of the material.

Practical classes are usually held at the end of the study of one or more topics of the course and have specific goals.

Firstly, it is the consolidation of knowledge in chemistry, including the main experimental material, by self-fulfillment certain experiences by students. At the same time, practical exercises conducted at the conclusion of a number of topics make it possible to successfully generalize the experimental and theoretical material, which is not always possible in a normal lesson.

Secondly, there is a further development of practical skills and mastery of the technique of a chemical experiment.

Thirdly, the creative application of knowledge is realized in the process of experimental problem solving and practical issues which is of great importance for the formation of skills to use knowledge in active form, to expand the horizons of students about the application of chemistry in life.

The skillful organization of a home chemical experiment contributes to the development of students' interest in chemistry, broadening their horizons, and more conscious assimilation of chemical knowledge. When assisting students in the organization of home laboratories, the teacher must inform the parents in order to avoid undesirable consequences when conducting experiments at home.

Entertaining experiments can occasionally be carried out in the classroom, but more often used in extracurricular activities in order to form and develop students' interest in chemistry. However, in no case should chemical experiments be turned into tricks, even when they are demonstrated in elementary grades. Therefore, applying an educational chemical experiment outside class work, it is necessary to widely use all types of experiment, including field experiments.

As field experiments, we can recommend qualitative reactions on the content of individual elements in objects external environment. The chemical reagents and utensils necessary for this are placed in special cases or boxes that allow them to be transferred or transported without any risk or damage. Each package contains instructions on the analysis technique, a pencil and a blank sheet of paper to complete the work.

A virtual experiment is recommended in cases where the initial substances are not available, the reactions take a long time, are accompanied by the release of hazardous substances, require complex equipment, etc. In addition, virtual experiences are useful before conducting real processes to ensure that students are fully aware of the upcoming experience. In any case, virtual experiences are based on imagination representations, and in order for them to be closer to actual phenomena, it is necessary to first form appropriate memory representations in students. A special form of virtual chemical experiment are experiments that can be designed and "carried out" using computer programs(Chem. Lab., Virtual Chemical Laboratory, etc.).

As in other natural science disciplines, an educational experiment in teaching chemistry aims to contribute to the solution of basic educational tasks, such as: mastering the basics of chemical science, getting to know its research methods and mastering special skills and abilities; formation and development of students' abilities, their cognitive and mental activity; polytechnic training and orientation of students to chemical professions; the formation of the worldview of students and the natural-science picture of the world in their minds; implementation of labor, moral, environmental education; comprehensive development of personality, etc.

According to many methodologists, the chemical experiment plays a leading role in successful solution educational tasks in teaching chemistry in many directions as an initial source of knowledge of phenomena, as a necessary, and often the only, means of proving the correctness or erroneousness of the assumption made, as well as confirming (illustrating) indisputable provisions reported by the teacher or learned by students from the textbook; as the only means for the formation and improvement of practical skills in handling equipment, substances, obtaining and recognizing substances; as an important means for the development, improvement and consolidation of theoretical knowledge; as a way to test the knowledge and skills of students; as a means of forming students' interest in the study of chemistry, developing their observation, curiosity, initiative, striving for independent search and improvement of knowledge and their application in practice.

An educational chemical experiment can be successfully applied at all stages of the educational process. First of all, the experiment provides visual acquaintance of students with the studied substances. For this purpose, samples of substances, collections in the form of handouts are demonstrated, experiments are conducted that characterize physical properties substances. After that, students begin to get acquainted with its chemical properties.

When explaining new material, the experiment helps to illustrate the topic under study not only with relevant chemical phenomena, but also with specific practical application as a result, students become more aware of theoretical basis chemistry.

Using the experiment to consolidate a new topic allows the teacher to identify how the new material is learned, and to outline a methodology and plan for further study of this issue.

The use of a home experiment helps to attract students to independent work using not only textbooks, but also additional, reference literature.

For the purpose of current, as well as final control and accounting of practical knowledge, one of the means is also a chemical experiment in the form of practical exercises for students and solving experimental problems. With the help of an experiment, many qualities of students can be assessed, ranging from the level of knowledge of theory to the practical skills of students.

Great opportunities in the education and upbringing of schoolchildren lie in the application of an educational experiment on electives, within the framework of specialized education and in extracurricular activities. Here, students are offered more complicated experiments, including those with a more pronounced polytechnic orientation.

The role of the educational chemical experiment in the formation of cognitive interest among students as a motive for cognitive activity should be especially emphasized, since it determines and directs all mental processes teachings: perception, memory, thinking, attention, etc.

The importance of using a chemical experiment when a teacher uses the method of problematic presentation of the material is great. The activity of the teacher here is to formulate the problem and reveal the evidence-based way to solve it through the setting of the experiment. At the same time, it is important that the students themselves come to the conclusion about the need to set up appropriate experiments, take part in their development and implementation. And the experiment here can act as the most important method of proving the truth or falsity of the hypotheses put forward.

The use of a chemical experiment allows students to master the practical skills established by educational standards as mandatory, including: technical (handling reagents, working with equipment, assembling devices and installations from finished parts and assemblies, performing chemical operations, observing safety rules) ; measuring (measurement of temperature, density and volume of liquids and gases, weighing, processing of measurement results); design (manufacturing of instruments and installations, their repair, improvement and graphic design).

With the help of the experiment, many qualities of students can be assessed, ranging from the level of knowledge of theory to the practical skills of students.

With all this, we must not forget that the chemical experiment, performing various didactic functions, can be used in various forms and must be combined with other methods and teaching aids. It is a system that uses the principle of gradually increasing the independence of students: from demonstrating phenomena through conducting laboratory experiments under the guidance of a teacher to independent work when performing practical exercises and solving experimental problems.

A chemical experiment develops thinking, mental activity of students. Often an experiment becomes a source of formed ideas, without which productive mental activity cannot proceed. In mental development, theory plays a leading role, but in unity with experiment, with practice.

2.2. Methodology and technique of educational full-scale experiment

To conduct school experiment there are certain methodological and technical requirements.

Demonstration experiments are carried out with the aim of creating in students certain ideas about substances, chemical phenomena and processes, followed by the formation of chemical concepts. However, demonstrations of experiments do not develop the required experimental skills and abilities in students, therefore, they must be supplemented by laboratory experiments and practical exercises.

A demonstration experiment is carried out when the experiment is complex and cannot be carried out by the students themselves; students do not own necessary equipment for this experience; laboratory experiments do not give the proper result; it is impossible to provide the necessary amount of equipment at the disposal of students; experiments pose some danger to students.

A demonstration experiment, regardless of who conducts it, a teacher or a student, must, first of all, be safe, both for the experimenter and for the observers. Other requirements that the experiment must meet include: visibility, the ability to see all the details and moments of the experience by all students, reliability, expressiveness, emotionality, persuasiveness, quick and simple execution. The demonstration experiment should be combined with the word of the teacher. In connection with these requirements, a number of methodological recommendations can be distinguished.

The teacher is responsible for the safety of students, so there must be funds in the classroom fire safety, fume hood for work with harmful and odorous substances, first aid products. Reagents for experiments should be checked in advance, the dishes for the experiment should be clean. When conducting dangerous experiments protective screen should be used.

The demonstration experiment should be carried out in flasks, beakers or large test tubes in order to chemical phenomenon could be observed from anywhere in the class. There should be nothing superfluous on the demonstration table. The teacher should not obscure the equipment and utensils with which he operates from the views of students with any objects. A lift table or overhead projector can be used.

The equipment for the demonstration of the experiment should not contain unnecessary details so that the attention of the trainees is not distracted from the chemical process. You should not get too carried away with spectacular experiences, as less spectacular experiences will no longer be of interest.

An experiment must always succeed, and for this purpose the technique of the experiment must be carefully worked out before it is carried out; all stages of the experiment should be thought out; negligence in the design of the experiment is unacceptable, it is necessary to foresee possible failures during the experiment and prepare for such cases spare parts of the equipment and reagents. Everything that is necessary for the experience should be at the teacher's fingertips. In case of failure, it is necessary to find out its cause, and repeat the experience in this or the next lesson. If possible, the experiments should be repeated several times so that the students remember them better, otherwise after a while the ideas received once will be erased from the memory of the students.

Any experience should be combined with the word of the teacher, since sensory perceptions alone cannot guarantee the development of correct ideas in students. In the process of observation, they can turn their attention not to the main features of an object or phenomenon, but to secondary or incidentally accompanying ones and, as a result, get an incomplete, fuzzy and even distorted idea of ​​the object under study. A more correct reflection of the real world, a more adequate perception becomes when the activity of thinking is added to the sensations, in this case guided by the word of the teacher.

The teacher is obliged to indicate to the students what and how they should observe during the experiment. If it is important for a teacher that students correctly perceive what he shows them, he must organize the observation process in advance, prepare students for it in advance, and then help correct perception during the experiment.

The combination of the experiment with the word of the teacher or student is carried out different ways, which are determined by various reasons, which can be illustrated in the form of algorithms.

When studying the physical properties of substances, the following algorithm is used: "Look and name (list)", that is, the teacher demonstrates a sample of the substance under study or gives students handouts, for example, aluminum samples, and asks to list the physical properties of the metal, determined directly by the senses ( state of aggregation, color, smell, etc.). The same technique can also be used when demonstrating the same type of properties of substances of the same class, for example, when demonstrating the effect of phenolphthalein on a KOH solution, if an experiment with a NaOH solution was previously demonstrated.

When studying more complex issues, which, however, can be relatively easily understood by students, the algorithm can be used: "Look; tell what you saw; explain this phenomenon." For example, when learning the concepts of hydrolysis of salts, the teacher demonstrates the effect of the indicator on various salts. Students see that the indicator colors salt solutions in different ways, and note that the environment of the solutions is different. The teacher asks to explain external signs experience, that is, to reveal the essence of the phenomenon, thereby creating a problem situation. Naturally, students cannot always answer the question posed by the teacher. The essence of hydrolysis is explained by the teacher later in the course of the conversation.

In the variants considered, the experiment (demonstration of experience) preceded a verbal discussion of what was seen. These options for combining words and visualization are called research.

Let's consider the reverse. When studying the properties of sulfuric acid, for example, a teacher might say: "Sulfuric acid in aqueous solution has properties typical of inorganic acids and reacts with metals, basic oxides, acids, salts." Then an appropriate demonstration or laboratory experiment is carried out. The algorithm for this combination of words and visualization can be expressed as follows: "The facts are as follows ... now look how it looks." This combination of words and visualization is called illustrative. When applied, the creation problem situation becomes more difficult in class.

The illustrative method is appropriate when explaining complex issues that require complete preliminary reflection and understanding on the part of students. For example, in order to experimentally substantiate the true graphical formula of ethanol, the teacher first discusses the possible variants of the formulas. The teacher then poses a problem: how to prove which formula corresponds to ethanol; conducts a thorough discussion of the issue theoretically; and only after that begins the experiment. After the experiment, a conclusion is drawn on the merits of the issue. This option is also illustrative, however, during its implementation, a large mental and cognitive activity of students takes place, which to a certain extent compensates for the main drawback of this approach - duration in time. The algorithm can be expressed as follows: "There is an inexplicable, incomprehensible fact or learning problem; hypotheses for solving the problem are expressed; a variant of the experiment is mentally developed to confirm (or refute) the hypothesis; the equipment is installed and the experiment is carried out; observations, necessary measurements, calculations are carried out; resolution conclusions are drawn original problem; additional tests are carried out if necessary.

The division of the methods of combining words and experience into illustrative and exploratory ones does not mean that the teacher does not say a word during the experiment. In any case, the teacher should explain the course of the experiment and direct the attention of students to the most essential in this moment process.

As a rule, demonstration experiments should not be lengthy. If it is not possible to choose an experience that is short in time, then it is best to demonstrate to students in the lesson several intermediate stages of the experiment and its final result.

Pauses arising while waiting for the result of the experiment should be used to organize a dialogue with schoolchildren, clarify the conditions for the experiment and the signs of chemical reactions.

Of great educational and upbringing importance is the experiment conducted by the students themselves (laboratory experiments, practical exercises, etc.), which also has a number of features. Compared with the teacher's demonstration experiment, it must be, of course, safe and feasible for each student to perform; to promote the development of skills and abilities of laboratory work technique, accuracy, discretion and careful attitude to materials and items of equipment; Encourage students to be creative in problem solving.

Laboratory experiments are carried out during the teacher's explanation according to his oral instructions. In this case, the algorithm is most often used: "Add A to substance (solution) B; observe carefully ...; write down your observations and reaction equations." The volumes of reagents used should be minimal so that only the planned reactions occur and the corresponding signs clearly manifest themselves for a sufficient time for the students to notice and fix them in memory.

There are two types of practical work (classes): conducted according to instructions and experimental tasks.

The instruction is an indicative basis for the activities of students. It details in writing each stage of the experiments should be described, instructions should be given on how to avoid possible erroneous actions, safety instructions for this work.

Before the students perform practical work according to the instructions, the teacher needs to clearly and briefly show them the necessary laboratory techniques and manipulations. This can be done in the process of preliminary preparation for practical work.

Experimental tasks do not contain instructions, but only a condition. Students must independently develop a solution plan and put it into practice, thereby obtaining a certain material result.

Before conducting a practical lesson, it is necessary to familiarize students with the designs of devices, methods of laboratory equipment, analyze the goals and content of the work and link this with homework on the analysis of instructions.

On the practical lesson at the beginning of the lesson, a brief conversation should be held about safety rules and the key points of work. On the demonstration table, you need to place assembled all the devices used in the work. Students are required to complete their work accordingly.

Requirements for holding entertaining experiences and the field experiment and the methodology for their implementation follow from the recommendations described above.

Significant problems in organizing an educational chemical experiment are compliance with safety regulations when performing experiments, cleaning the workplace, washing dishes and disposing of used reagents.

2.3. Unification of the educational experiment

Under the unification of a chemical experiment in education, we mean a rational reduction in the types of instruments and installations with which experiments are carried out. In the proposed device (sometimes with additions or changes), it is possible to successfully carry out various chemical reactions both during the demonstration experiments and during the student experiment.

The basis of the device is a flask or flask with a capacity of 50-200 ml, a stopper with a separating funnel (respectively, a flask) of 25-100 ml, the device must have a gas outlet tube. A variety of modifications of the unified device are possible (using Wurtz, Bunsen flasks, etc.) (Fig. 2).

Rice. 2. Some modifications of the unified device.

The use of this installation ensures the safety of chemical experiments, since the release of gaseous and volatile toxic substances it is possible to regulate them quantitatively and send them either directly for carrying out reactions involving these gases, or for trapping by absorption devices.

Another advantage of this device is the ability to quickly and accurately dose the initial substances used for the experiment. Substances and solutions are placed in flasks and separating funnels in advance, before the start of classes, in required quantity, and not by eye, as is usually the case when demonstrating experiments in test tubes or glasses, when substances and solutions are collected directly in the lesson during the demonstration of experiments.

When using the device, the perception of experience is achieved by all students, and not only by those who sit at the first desks, as is the case when conducting experiments in test tubes. The recommended device allows you to carry out qualitative and quantitative experiments in chemistry at school, as well as in secondary special and higher educational institutions. Let us illustrate the fundamental application of the device on the example of some experiments, grouping them according to similar features.

Getting gases. Most of the gases studied at school are based on heterogeneous reactions between solid and liquid phases. The solid phase is placed in a flask, which is closed with a stopper with a funnel and a gas outlet tube. An appropriate solution or liquid reaction reagent is poured into the funnel, the addition of which to the flask is dosed using a separating funnel tap. If necessary, the flask with the reaction mixture is heated, adjusting the volume of the evolved gas and the reaction rate.

Using the device and appropriate reagents, it is possible to obtain oxygen, ozone, chlorine, hydrogen, carbon dioxide, carbon monoxide and sulfur dioxide, hydrogen halides, nitrogen and its oxides, nitric acid from nitrates, ethylene, acetylene, bromoethane, acetic acid from acetates, acetic anhydride, esters and many other gaseous and volatile substances.

Naturally, at the same time when receiving gases with the help of the device, it is possible to demonstrate their physical and Chemical properties.

Reactions between solutions. It is convenient to carry out experiments in this device, in which the addition of a liquid reagent must be carried out in small portions or dropwise, when the course of the reaction is affected by an excess or deficiency of one of the starting substances, etc., for example:

Dissolution of sulfuric acid in water and compliance with safety rules during this operation;

Experiments illustrating the diffusion of substances in liquids or gases;

Definition relative density mutually insoluble liquids and the formation of emulsions;

Dissolution solids, the phenomenon of flotation and the formation of suspensions;

Salt hydrolysis reactions, if it is important to show the change in the degree of hydrolysis depending on the volume of water added to the salt solution;

Experiments illustrating the color of indicators in various environments and neutralization reactions;

Reactions between electrolyte solutions;

Reactions, long in time;

Reactions of organic substances (bromination and nitration of benzene, oxidation of toluene, production of soap and aniline, hydrolysis of carbohydrates).

Demonstration characteristic properties the substance under study. With the help of the device, it is possible to demonstrate consistently and clearly, with a minimum expenditure of time, the characteristic physical and chemical properties of the substance under study. At the same time, reagents are saved, the necessary safety of the experiment is achieved (the emitted harmful gases and volatile substances are captured by the appropriate absorption solutions), and a better perception of the experiment by all students of the class is ensured.

Consider the preparation and conduct of an experiment in demonstrating the properties of hydrochloric acid. Before the lesson, the teacher prepares the required number of flasks (according to the number of reactions studied) and one stopper with a separating funnel and a gas outlet tube in it. Substances or solutions (zinc, copper, copper (II) oxide, copper (II) hydroxide, sodium hydroxide solution with phenolphthalein, sodium carbonate, silver nitrate solution, etc.) are placed in the flasks in advance. About 30 ml of a solution (10-20%) of hydrochloric acid is poured into a separating funnel. During the lesson, the teacher only needs to rearrange the cork with a separating funnel filled with acid from one flask to another, spending 3-5 ml of solution for each reaction.

If toxic volatile compounds are formed during the reactions, then the gas outlet tube of the device is immersed in the appropriate solutions to absorb these substances, and the reaction mixture in the flask is neutralized after the end of the experiment.

Solubility of gases in water. Let us consider the demonstration experiment of the solubility of gases in water using the example of sulfur oxide (IV). Two devices are required for the experiment. In the first device (in the flask - sodium sulfite, in the separating funnel - a concentrated solution of sulfuric acid) sulfur oxide (IV) is obtained, which is collected in the flask of the second device by the method of air displacement. After filling this flask with gas, water is poured into the funnel, the gas outlet tube is lowered into a glass of water, tinted with purple litmus or another indicator (Fig. 3).

Rice. 3. Demonstration of the solubility of gases.

If we now open the clamp or valve of the gas outlet tube, then due to the small contact surface (through the inner opening of the tube) of sulfur oxide (IV) and water, a noticeable dissolution of the gas with subsequent fountaining of liquid into the flask does not occur immediately, but after a rather long period of time, until the flask will not create sufficient vacuum.

To speed up this process, 1-2 ml of water is poured from the funnel into the flask (with the clamp on the gas outlet tube closed) and shaken gently.

This volume of water is quite enough for the pressure in the flask to decrease, and the water tinted with the indicator, when the clamp is removed from the gas outlet tube, rushes into the flask with a fountain, changing the color of the indicator. To enhance the effect, the flask can be turned upside down, having previously closed the separating funnel with a stopper and without removing the gas outlet tube from a glass of water.

Discoloration of dyes. About 0.5 g of potassium permanganate is placed in the flask of the device. AT lower part corks are injected with two needles, on which they prick a piece of dyed fabric or a strip of litmus paper. One of the samples is moistened with water, the second is left dry. The flask is closed with a stopper, a few milliliters of concentrated hydrochloric acid are poured into the separating funnel, the gas outlet tube is lowered into a solution of sodium thiosulfate to absorb the excess chlorine released (Fig. 4).

During the demonstration of the experiment, the faucet of the separating funnel is slightly opened and the acid is poured dropwise into the flask, then the faucet is closed again. In the flask, a reaction takes place between substances with the release of chlorine, a wet cloth or a strip of litmus paper discolors quickly, and a dry sample - later, as it is moistened.

Rice. 4. Demonstration of discoloration of dyes.

Note. Many fabrics are dyed with chlorine- and other bleach-resistant dyes, so pre-testing and pre-selecting appropriate fabric samples is essential. In the same way, the discoloration of dyes by sulfur dioxide can be shown.

Adsorption properties of coal or silica gel. About 0.5 g of powder or shavings of copper is placed in the flask. A piece of metal wire with a bent end is injected into the lower part of the plug, to which a small mesh is attached to hold the activated sorbent weighing 5–15 g (Fig. 5).

Rice. 5. Installation for demonstrating gas adsorption.

The flask of the device is closed with a stopper prepared in this way, and nitric acid is poured into the funnel. A gas outlet tube equipped with a clamp (the clamp is open before the start of the experiment), dropped into a glass with colored water. After assembly, the device is checked for leaks. At the time of the demonstration of the experiment, the faucet of the separating funnel is slightly opened and a few drops are poured out acid into a flask in which a reaction occurs with the release of nitric oxide (IV). Do not add an excess of acid, it is necessary that the volume of the released gas corresponds to the volume of the flask.

After the end of the reaction, which is determined by the cessation of the release of bubbles of air displaced from the flask through the gas outlet tube, the clamp on it is closed. The device is installed in front of a white screen. The adsorption of nitric oxide (IV) in the flask is judged by the disappearance of the color of the gas. In addition, due to the formation of a certain vacuum in the flask, liquid from the glass is sucked into it if the clamp is opened on the gas outlet tube.

Experiments on the study of the electrical conductivity of substances and solutions. If we pass two additional metal or, better, two graphite rods (electrodes) through the stopper of the device, the lower ends of which almost touch the bottom of the flask, and connect them through a light bulb or galvanometer to a current source, then we get an installation for determining electrical conductivity solutions of substances and the study of the provisions of the theory electrolytic dissociation(Fig. 6).

Rice. 6. Device for determining the electrical conductivity of solutions.

Quantitative experiments based on reactions occurring with the release of gases. If you bring the gas outlet tube of the device under a graduated cylinder with water installed in a crystallizer with water, and collect the gas released during the reaction by displacing water, then by the volume of the resulting gas, you can carry out quantitative calculations to establish the molar masses of substances, confirm the regularities chemical kinetics and thermochemistry, determining the formula of ethanol and other substances, etc. (Fig. 7). If the gas released during the reaction dissolves or reacts with water, then other liquids and solutions must be used in the experiments. The examples given do not exhaust all the possibilities of the proposed unified device in the educational chemical experiment. If you have in stock plugs with two gas outlet tubes or with two separating funnels, as well as other installation options, then the number of experiments using a unified device can be significantly increased, which will contribute to the scientific organization of labor

chemistry teacher.

Rice. 7. Device for carrying out quantitative experiments with gases.

Note . Component parts of the instrument: flasks, graduated separating funnels, stoppers, clamps, etc. - should be included in typical sets of utensils and equipment for school classrooms chemistry and educational chemical laboratories pedagogical higher educational institutions.

Using a virtual laboratory for distance learning in a chemistry lesson

It so happened that due to the specifics of the school where I work, several students ended up outside our country for a long time. Someone left for treatment, someone for training, and there are those who left for family reasons. The educational process for such students is not interrupted, but goes to another level. H help for these students comes d distance learning, which is the only possible learning option.Technology distance learning lies in the fact that training and control over the assimilation of the material takes place with the help of the Internet, using on-line and off-line technologies.The possibility of implementing distance learning is the use of various computer programs. This is both Skype and i-school, Email, finally, but in chemistry, an experiment is important, where on laboratory classes theory is applied, and, in addition, practical skills are formed in conducting, processing and presenting results. Then the virtual laboratory comes to the rescue for our students.

A chemical experiment is a specific means of teaching chemistry, acting as a source and the most important method knowledge, he introduces students not only to objects and phenomena, but also to the methods of chemical science. In the process of a chemical experiment, students learn not only to observe, compare, analyze, but also to properly use laboratory equipment, get acquainted with chemical glassware and instruments, acquire skills and abilities. The ability to conduct, observe and explain a chemical experiment, handle substances and equipment is one of the most important components chemical literacy.

A virtual laboratory is a program that allows you to simulate chemical processes on a computer, change the conditions and parameters of its implementation. Such a program creates special opportunities for the implementation of interactive learning. Virtual laboratories can be classified according to the degree of interactivity, which characterizes the depth of the learning interaction of students with a computer program.

The difference between a virtual chemical experiment and a natural one is that when using the first one, the images of substances and equipment are operated on. Virtual laboratory work is a software and hardware complex that allows you to conduct experiments without direct contact with reagents and chemical equipment. Thus, a virtual laboratory in teaching chemistry is presented as a computer simulation of an educational chemical laboratory.

There are several principles to consider when choosing virtual labs. They should be accessible, free of charge, easy for learners with user-level computer skills, and fit for purpose.

Virtual labs - advantages and disadvantages.

Compared to traditional labs, virtual labs have a number of advantages.:

• There is no need to buy expensive and unhealthy reagents. For example, for laboratory work on organic chemistry fume hoods are required with some substances.
• There is no need to store these substances in a separate room under certain conditions (metal cabinets, separate shelves, etc.).
• Virtual labs have a more visual visualization of physical or chemical processes. The experiment can be repeated several times without spending reagents.
• The ability to conduct an experiment at "your" pace, with a break, without fear of changing the result due to side reactions. This is important for hyperactive and restless students, as well as those with cerebral palsy.
• Security. It is possible to conduct experiments with toxic and explosive chemicals (for example, when studying halogens, alkali metals). And for children with disorders of the musculoskeletal system, this is still the absence of fear of spilling, spilling, not holding in their hands.
• Saving study time: a) the work can be done independently as homework; b) no time is spent at the entrance of the lesson to organize the experiment.
• Training in compliance with safety requirements in safe environment virtual laboratory.
• Students can independently practice the topic of a particular section at a convenient time for them, without limiting themselves to the lesson
• Harmlessness. For students suffering from allergies, pulmonary diseases, this is an opportunity to perform an experiment without harming their health.
• When conducting a number of practical work, students can use video clips that allow them to see the experiment in a real laboratory.

However, virtuallaboratory works also have disadvantages. The main one is the lack of direct contact with the object of study, instruments, equipment.

The main virtual laboratories used in distance learning

1. Free on-line resource Virtulab.Net - one of the portals dedicated to virtual educational laboratories. The site offers educational interactive works that allow students to conduct virtual experiments in chemistry, biology, ecology, physics and other subjects.
2. Free resource Single collection DER - interactive laboratory work in chemistry and other subjects. Data educational resource can be used both online and offline.
3. A series of discs published by the Drofa publishing house: Laboratory work in chemistry for grades 8-11.

Summarizing all of the above, we can say that virtual laboratories can be used both in the classroom and in self-preparation for classes, they allow a deeper understanding of the laws of chemistry, as well ascontribute to the development of research and experimental skills. The application of chemical knowledge and skills is necessary for every person to solve the practical problems of everyday life.

LITERATURE

Belokhvostov AA, Arshansky E. Ya. Electronic means of teaching chemistry; development and method of use. -Minsk, Aversev, 2012

Gavronskaya Yu. Yu., Oksenchuk V. V. Methodology for creating virtual papers in chemistry:Modern problems of science and education,http://www.science-education.ru/ru 2015

Trukhin A.V. Types of virtual computer laboratories // Open and Remote education. - 2003. - №3(11).

Pak M. S. Theory and methods of teaching chemistry: a textbook for universities. - St. Petersburg, Herzen State Pedagogical University, 2015

With the widespread introduction of information technology in the educational process, many teachers have questions: “Is a computer really needed in physics lessons? Will computer simulations replace the real experiment from the educational process? The teachers of our school believe that the use of a computer in the classroom is justified, first of all, in those cases in which it provides a significant advantage over traditional forms learning. I completely agree with them. One such case is the use of computer models and virtual laboratories.

What is the advantage of computer simulation in comparison with a full-scale experiment? Computer modeling makes it possible to visually illustrate experiments and phenomena, to reproduce their subtle details that may be unnoticed by an observer in real experiments. The use of computer models and virtual laboratories is provided as a unique opportunity to visualize a simplified model of a real phenomenon. In this case, additional factors can be gradually included in the consideration, which gradually complicate the model and bring it closer to the real phenomenon. In addition, the computer allows you to simulate situations that are not realizable experimentally.

For example, when studying the topic “Nuclear Reactor” in grade 11, I use the “Nuclear Reactor Operation” model from the educational electronic edition“Physics grade 7-11. Practicum” by the PHYSICON company, which vividly and clearly presents the processes occurring during the operation of a nuclear reactor. The work of students with computer models and virtual laboratories is extremely useful, as they can set up numerous experiments and even conduct small studies. Interactivity opens up huge cognitive opportunities for students, making them not only observers, but also active participants in ongoing experiments. The process of computer modeling for students is fascinating and instructive, since the result of modeling is always interesting, and in some cases it can be quite unexpected. By creating models and watching them in action, students can become familiar with many phenomena, study them at a qualitative level, and also conduct small-scale research. Of course, a computer lab cannot replace a real physics or chemistry lab.

Nevertheless, when performing computer laboratory work, schoolchildren develop skills that will be useful to them for real experiments - choosing the conditions for experiments, setting the parameters of experiments, etc. All this turns the performance of many tasks into micro-research, stimulates the development creative thinking students, increases their interest in the subjects of the natural science cycle. The work of students with computer models is useful because, due to the possibility of changing the initial conditions of experiments over a wide range, computer models allow them to perform numerous virtual experiments. Some models allow simultaneously with the course of experiments to observe the construction of the corresponding graphical dependencies, which increases their clarity. Such models are of particular value, since students, as a rule, experience significant difficulties in constructing and reading graphs.

As an example, we can cite the model "Uniformly accelerated motion of the body" from the above named disk. In this model, in addition to a moving athlete, who, in accordance with the given initial conditions, slows down, turns around and picks up speed in the opposite direction, the length and direction of his speed vector change accordingly, and graphs of the coordinate, displacement module and speed projection are plotted in dynamic mode. Moreover, such an independent research activities is so interesting and exciting for them that the issues of ensuring discipline and attention do not arise at all.

Of course, computer demonstrations will be successful if the teacher is working with a small group of students who can be seated close to the monitor. Since the number of computers and the number of classes in our school is small, I have the opportunity to widely use information technology in educational process. At the same time, I use computers for self-study students (studying notes, watching videos, conducting practical work). I conduct class laboratory work (in a computer class), independent practical work of students (solving examples from a database of questions and tasks), prepare materials for conducting tests in the traditional ("paper") version in the classroom, to prepare for the lesson or control work, for students to perform creative work under the guidance of a teacher, as well as independently. Computer models easily fit into the traditional lesson and allow the teacher to organize new types of learning activities.

As examples, I will give three types of lessons using models that I have tested in practice. th- solving problems with subsequent computer verification of the answers received. You can offer students for independent solution in the classroom or as homework tasks, the correctness of the solution of which they can check by setting up computer experiments. Self-verification of the results obtained with the help of a computer experiment enhances the cognitive interest of students, makes their work creative, and in some cases brings it closer in nature to scientific research. As a result, at the stage of consolidating knowledge, many students begin to invent their own problems, solve them, and then check the correctness of their reasoning using a computer. Tasks compiled by schoolchildren can be used in class work or offered to other students for independent study in the form of homework.

Lesson of generalization and systematization of knowledge- research. At the stage of generalization and systematization of new material, students are invited to independently conduct a small study using a computer model or a virtual laboratory and obtain the necessary results. Computer models and virtual laboratories make it possible to conduct such a study in a matter of minutes. Of course, the teacher formulates research topics, and also helps students in the stages of planning and conducting experiments.

Lesson of complex application of ZUN- computer laboratory work. To conduct such a lesson, it is necessary, first of all, to develop appropriate handouts, that is, laboratory work forms. Tasks in the work forms should be arranged as their complexity increases. First, it makes sense to suggest simple tasks of an introductory nature and experimental tasks, then computational tasks and, finally, tasks of a creative and research nature. I note that tasks of a creative and research nature significantly increase the interest of students in studying subjects and are an additional motivating factor. For this reason, the lessons of the last two types are especially effective, since students gain knowledge in the process of self-study. creative work. They need this knowledge to obtain a specific result visible on a computer screen. The teacher in such cases is only an assistant in creative process knowledge formation.

Recently, much has been said about the individual approach to teaching students. How can an individual approach be implemented when using computer models in the educational process? At individual work students with great interest "tinker" with the proposed models, try their adjustments, conduct experiments. Let's consider the types of tasks for computer models from the point of view of their use when working with gifted and poorly performing students. For example, introductory tasks, simple computer experiments, experimental and qualitative tasks are more suitable for weak students. While calculation tasks followed by a computer check are suitable for both weak and gifted students. In this case, everything depends on the complexity of the proposed tasks.

But ambiguous tasks, tasks with missing data, creative, research and problem tasks are more suitable for strong students. Although, if the teacher can provide significant assistance to weak students, then they can overcome some of these tasks. The most capable students can be offered research tasks, that is, tasks during which they will need to plan and conduct a series of computer experiments that allow them to confirm or refute certain patterns. The strongest students can be invited to independently formulate such patterns. It should be noted that in the lessons creative tasks for inventing their own tasks enjoy great and constant success, both among strong and poorly performing students.

In addition, I widely use information technology not only in the classroom, but also in extra classes. Particularly when preparing students for final certification in the form of an exam.

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