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2
УДК 372.85
Usmonov B.X.
Teacher academician lyceum at Tashkent Pediatric Medical Institute Uzbekistan, Tashkent city METHODOLOGY OF STUDYING THE THEME «HYDROGEN PRODUCTION, ITS PHYSICAL AND CHEMICAL PROPERTIES» Annotation: In this article, the problem of the technique of studying the topic of "obtaining hydrogen, an ego ofphysical and chemical properties" Keywords: chemistry, hydrogen, methodology, system
Усманов Б.Х. преподаватель, академик лицей при Ташкентском Педиатрическом Медицинском
Институте Узбекистан, г. Ташкент МЕТОДИКА ИЗУЧЕНИЯ ТЕМЫ «ПОЛУЧЕНИЕ ВОДОРОДА, ЕГО ФИЗИЧЕСКИЕ И ХИМИЧЕСКИЕ СВОЙСТВА» Аннотация: В этой статье рассматривается проблема методика изучения темы «получение водороды, эго физического и химического свойства»
Ключевые слова: химия, водород, методика, система
The study of hydrogen begins with the production of it. The teacher demonstrates the experience, and the students describe their observations, noting the "boiling" of the acid when it comes in contact with zinc. This fact makes it possible, in discussing these experiments, to draw the students' attention to the fact that external manifestations of processes different in essence may be similar. We should talk about boiling, as a physical phenomenon. Students should remember the definition of boiling as a transition from a liquid state to a gaseous state. When the liquid boils, its vapors in the form of bubbles come to the surface and mix with the surrounding air. When cooled, condensation of vapors into the liquid takes place. The molecules do not change, the new substance is not formed. The teacher can lead the students to a conclusion about the qualitatively different nature of the observed phenomenon. Can we assume that the observed phenomenon is not boiling? Heating was not carried out, the substances only touched each other (zinc with hydrochloric acid). And this is one of the conditions of a chemical reaction. How to prove that the gas produced is a new substance? First of all, it should be checked whether it supports combustion, like oxygen, and does not extinguish the lit charcoal as carbon dioxide. As a result of the experiments, a new property is revealed: hydrogen-a combustible gas. Since neither zinc nor acid possesses such a property, it means that the gas-g formed during their interaction is really a new substance.
You can discuss with students the question of which substance hydrogen is
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released from. Observations show that gas bubbles break away from the surface of the metal. G. Cavendish, who discovered hydrogen, believed that metal is a source of gas. Students, however, know that metals are simple substances. If we carry out a series of experiments showing how different metals interact with the same acid and the same metal with different acids, then it is possible to observe hydrogen evolution in all cases. Based on these observations, students will conclude that hydrogen is a part of acids. But why does the reaction go on the surface of the metal? The question makes one again pay attention to the fact that it is the metal surface that comes into contact with the acid and the metal atoms drive out hydrogen from it. How to confirm the correctness of the output? Students often suggest changing the size of the contact surface of the metal with acid. They suggest that with an increase in the surface the reaction will go faster, and with a decrease, it will be slower. The reasoning is conducted by analogy with what happens in the process of burning various types of fuel. The teacher can again conduct the experiment, while simultaneously dropping into the same solutions of the acid taken in equal amounts, the same weights of metal, but in one case the metal is in the form of an entire plate, and in the other - several pieces of metal or powder. So we can conclude that the reaction rate depends on the quantitative factor - the contact surface area of the reacting substances.
The teacher must experimentally prove the formation of a complex substance of zinc chloride. After the students independently determine the type of the ongoing reaction and examine its essence from the point of view of the atomic-molecular theory, the teacher can note that there are two mutually opposite but related processes: the separation of hydrogen and chlorine in HC1 molecules and the chlorine compound and zinc, resulting in the formation of zinc chloride. Any chemical reaction is a unity of two opposing processes.
Discussing the design and operation of devices for collecting and collecting hydrogen, the teacher must rely on the knowledge of the students about the cause-effect relationship and discuss the question of the conformity of the device design to their purpose.
When obtaining hydrogen and studying its physical properties, it is necessary to compare them with the physical properties of oxygen and to conclude that there is a difference and similarity in the ways in which these gases are collected into vessels.
In a comparative study of the chemical properties of hydrogen and oxygen, it is necessary to draw the students' attention to the fact that hydrogen and oxygen enter into chemical reactions with both simple substances and complex ones. Hydrogen exhibits properties of a reducing agent, and oxygen-oxidizer. Hydrogen and oxygen as simple substances have opposite chemical properties: hydrogen burns in the air, and oxygen does not burn, but supports the combustion of other substances. Interacting with each other, hydrogen and oxygen form a completely unlike new substance - water, which does not burn and does not support burning.
When studying the chemical properties of hydrogen, it is important to show to students that one and the same reaction, depending on the conditions, can take
place at different rates and have different characteristics, although the essence will be the same. For example, the interaction of oxygen and hydrogen with the formation of water goes and under normal conditions, but extremely slowly, and therefore imperceptibly. If hydrogen is ignited, then it gently burns in the air and in oxygen, forming water. A mixture of hydrogen with oxygen when ignited or heated above 550 ° C explodes. If a metal-platinum mixture is introduced into the mixture of hydrogen and oxygen, the mixture is heated, water vapor forms, which then settle in the form of droplets on the walls of the vessel. However, the conditions and signs are different. It should be noted the catalytic role of platinum.
Knowledge of these factors is necessary not only for students to pay attention to the conditions that affect the time of the passage of reactions, but to notice the possibility of controlling chemical transformations, the connection between theory and practice.
The interaction of copper (II) oxide with hydrogen can be treated in different ways. In one case, you can demonstrate the experience, discuss its results, and make an appropriate generalization. In another case, students' knowledge can be more actively used. Since they are already familiar with the physical properties of copper (II) oxide, copper, hydrogen and water, the teacher can invite them to predict the signs of a chemical reaction between copper (II) oxide and hydrogen, record its equation and determine the type of reaction. It is important to dwell on the role of hydrogen in this reaction. After all, students often notice only such a side of the reaction as a compound, hydrogen with oxygen to form oxide (H2O), i.e., oxidation. The teacher can consider the reaction as redox, show the unity of the processes of hydrogen oxidation and reduction of copper, indicate the role of hydrogen and copper (II) oxide as a reducing agent and oxidizer. This can be noted as another confirmation of the unity of opposites characterizing the reaction as an internally contradictory process in which the opposite substances (the oxidizer and the reductant) interact (interact). It should also be noted that the reaction under consideration is attributed to the type of substitution reactions, but at the same time it is also called the redox reaction. So the teacher confirms the possibility of considering chemical transformations from different points of view.
To consolidate knowledge of hydrogen production in the laboratory and its physical and chemical properties, it is possible to invite students, in addition to assignments from the textbook, to design devices for obtaining hydrogen from the issued parts and to discuss the advantages and disadvantages of devices or their projects. A great training and developing role is played by the exercises for performing a number of substance conversions: make up the reaction equations and specify the conditions for the following transformations:
It makes sense to explain to students what to do with the selection of interacting substances. The main solution to this issue is to analyze the composition of the starting material and the reaction product, because the reaction products include the atoms of the starting materials.
Used sources:
1. SU № 1453850, С 07 Д 295/02, 1988г.
2. патент 6133299 США, МПК7 А 61 К 31/44, заявл. 25.02.1993г., опубл. 17.10.2000г.
3. J. Med. Chem., 2001, 44, № 5, p. 694-702.
4. Rev. Roum. Chem., 1997, 22, № 6, p. 885-898.
УДК 372.862
Xalmuratova M.T. Tashkent State Dental Institute Uzbekistan, Tashkent city
METHODICAL RECOMMENDATIONS FOR USING THE METHOD OF
WORK IN SMALL GROUPS
Annotation: In the present article methodical recommendation on using the method of working in small groups have been reflected, as working in small groups enables the student to develop the skills of cooperation and teach them to solve occurring compromises.
Key words: innovational pedagogy, interactive education, personal-oriented approach, compromise.
Халмуратова М. Т.
Ташкентский Государственный Стоматологический Институт
Узбекистан, г. Ташкент МЕТОДИЧЕСКИЕ РЕКОМЕНДАЦИИ ПО ИСПОЛЬЗОВАНИЮ МЕТОДА РАБОТЫ В МАЛЫХ ГРУППАХ
Аннотация: В данной статье даются методические рекомендации по использованию метода работы в малых группах, так как занятия в малых группах позволят студентам развивать навыки сотрудничества и научат разрешать возникающие между ними разногласия.
Ключевые слова: инновационная педагогика, интерактивное обучение, личностно - ориентированный подход, компромисс
In recent years, the educational process is widely used new technologies and teaching methods. Progress in the educational system brings to the arena a new direction - innovative pedagogy and new pedagogical technologies.
The new pedagogical technologies in the educational process, first of all, are connected with the personality of the teacher, his pedagogical skill, his spiritual and social level. It seems to us that the main thing in the profession of a teacher is the formation of a professional orientation. This statement not only does not belittle the importance of the teaching profession, but, on the contrary, opens the possibility for everyone who wants to master it. The rejection of stereotyped classes implies a transition to a new stage of learning, interactive learning, interactive learning.
Interactive learning is learning, built on the interaction of all students,
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