Practical lesson in grade 9 as part of the elective course "Analyst" on the topic "Analysis mineral water».

Shuvalova Elena Borisovna, chemistry teacher

The purpose of the lesson : Teach students the practice of qualitative analysis, teach them to draw practical conclusions from the analysis.

Tasks:

1. To consolidate the knowledge of students about qualitative reactions to cations and anions;

2. To consolidate the ability of students to compose the equations of reactions in molecular and ionic form;

3. Improve the ability to explain the observations and results of chemical experiments;

4. To consolidate the knowledge of students about safety rules when handling chemical reagents;

5. To teach to identify intersubject connections, to find cause-and-effect relationships;

6. To develop logical thinking: the ability to compare, highlight the main thing, generalize, draw conclusions.

Lesson type : practical lesson.

Organizational form: research lesson.

Methods: partial search, research.

Reagents and equipment: laptop, projector, screen, bottles with mineral water.

On student tables:

1.Glasses with samples of mineral water No. 1,2,3;

2. solutions of potassium carbonate, barium chloride, hydrochloric acid, silver nitrate;

3.alcohol, matches, holder, copper wire, test tubes;

4.Universal indicator.

During the classes

(lesson epigraphs on chalkboard)

Experience is the teacher Water! This is not to say what is needed for

Eternal life. life, you are life itself ...

I. Goethe You are the greatest wealth in the world.

A. De Saint-Exupery

On the screen - SLIDE number 1

The main stages of the lesson

1. Organizational moment. Statement of the problem and tasks of the lesson.

2. The teacher's story about mineral water.

3. Conducting a chemical experiment. Pupils work in pairs.

4. Summing up the results of the experiment.

5. Conclusions from the lesson.

The purpose of our lesson is to analyze mineral water. But first we will talk about what mineral water is, get acquainted with the history of its use, recall the deposits of mineral water in Russia, find out what classes mineral water is divided into according to its composition and properties. Write the topic of the lesson in your notebooks.

What is mineral water?

SLIDE number 2

Mineral they call water from underground sources, which contains certain dissolved mineral salts.

This is rainwater, which many centuries ago went deep into the earth, seeping through the crevices and pores of different layers of the rock. At the same time, various mineral substances in the rock were dissolved in it.

Mineral waters differ from just natural water from underground sources and open reservoirs in composition. The deeper they lie, the warmer and richer in carbon dioxide and minerals. In addition, the deeper the water penetrates into the rock, the more it is purified. In such water, minerals accumulate naturally as they pass through geological fractions.

The history of the use of mineral water.

SLIDE number 3

People have used the waters of healing springs since time immemorial. They used mineral water in both medicinal and preventive purposes, for outdoor and indoor use.

The first mention - in the Indian Vedas (XV century BC)

In ancient times, the Greeks built sanctuaries at the healing springs dedicated to the god Asclepius, the patron saint of medicine.

The ancient Greeks believed that Hercules acquired his heroic strength by bathing in the magical source of the Caucasus.

It was in Greece that archaeologists discovered the ruins of an ancient hydropathic establishment built in the 6th century. BC. The remains of ancient baths are also found in the Caucasus, where they not only bathed, but were also treated with mineral waters. Legends about the miraculous power of water have been passed down from generation to generation. This is evidenced by the names of mineral springs. So "Narzan" in translation from Balkar means "heroic drink".

SLIDE number 4

The history of the study and use of mineral waters in Russia is connected with the name of Peter I, who ordered by his decree to search for spring waters in Russia about three hundred years ago. Expeditions to the Caucasus discovered the sources of Pyatigorye and Borjomi.

Peter I, besides other achievements of the West, liked European resorts located near mineral springs. By his order, the first hydrotherapy resort in Russia was built on the Marcial (ferruginous) waters in the Olonets province in Karelia.

Peter himself was repeatedly treated with these waters and, on his order, the first "Doctoral rules, how to act in these waters" were drawn up.

SLIDE number 5

In 1803, Alexander I recognized the state importance of the Caucasian mineral waters and began to study their healing properties.

Mineral water deposits in Russia.

SLIDE number 6

Let's look at a map of Russia showing the main deposits of mineral springs on its territory.

This is of course the Caucasian mineral waters, Krasnodar region, Western Cis-Urals, Perm region, Samara region, Urals, Trans-Urals, Transbaikalia, Kamchatka, Kuril Islands, Sakhalin, Novgorod region (Staraya Russa), Moscow and Ivanovo regions, Leningrad region (Polyustrovo), etc.

Mineral water classification.

SLIDE number 7

According to its consumer properties, water is divided into

Drinking purified (salts less than 0.5 grams per liter)

Dining room (more than 1 gram of salt per liter)

Medical - dining room (salts from 1 to 10 grams per liter)

Medicinal (salts more than 10 grams per liter)

Such waters also include waters with a high content of one or several biologically active elements (Fe, H 2 S, J, Br, F), while the total mineralization may be low.

SLIDE number 8

Classification by ionic composition.

Seven main ions are widely distributed in natural waters: HCO 3 -, CI -, SO 4 2-, Ca 2+, Mg 2+, K +, Na +.

Hydrocarbonate

Chloride

Sulphated

Calcium

Magnesium

Sodium (this group includes water according to the total content of sodium and potassium ions)

What effect does this or that group of water have on the body?

SLIDE number 9

HYDROCARBONATE - reduce the acidity of gastric juice, they are used in the treatment of urolithiasis.

CHLORIDE - stimulate metabolic processes in the body, are used for disorders of the digestive system.

SULPHATE - stimulate motor skills gastrointestinal tract, have a beneficial effect on the regenerative functions of the liver and gallbladder.

Most waters are of mixed structure.

SLIDE number 10

CALCIUM - is the basis bone tissue, affects blood clotting.

MAGNESIUM - participates in the formation of bones, regulation of the work of nervous tissue, metabolism of carbohydrates, improves blood supply to the heart muscle.

SODIUM - participates in the regulation of blood pressure, water metabolism, activation of digestive enzymes.

POTASSIUM - activates the muscular work of the heart and the work of a number of enzymes.

So, today you have to conduct a qualitative analysis of mineral water. On your tables there are samples of mineral water in glasses No. 1, 2, 3. You need to carry out qualitative reactions for the seven main ions that may be contained in mineral water and draw a conclusion about the composition of each sample. The results of the experiments carried out should be entered in the table.

SLIDE number 11

Let's remember the qualitative reactions to ions that may be contained in mineral water. (students list qualitative responses)

When performing any chemical experiment, you must follow the safety rules. What safety rules do you think you should follow today when performing experiments? (students' answers)

But before getting down to practical work, a few tips for solving experimental problems.

Do not start the experiment until you have made a plan for it.

Be sure to write down your observations.

Take small samples of substances for the experiment.

During the experiment, do not disturb others: do not shout, do not meddle with a neighbor with advice, do not invite the whole class to see what you have done.

Conducting a chemical experiment. Pupils work in pairs.

So, let's summarize the work. (students name the ions that are contained in the proposed samples of mineral water)

No. 1 (HCO 3 -, CI - , minor amounts of Ca 2+ and Mg 2+, Na +, K +)

No. 2 (HCO 3 -, SO 4 2-, CI -, Ca 2+, Mg 2+, K +, Na +)

No. 3 (minor amounts of HCO 3 - and CI -)

The teacher opens the closed labels on bottles with mineral water before the lesson.

Bottle No. 1 - "Essentuki - 17" is a medicinal water.

Bottle No. 2 - "Narzan" is a medicinal table water.

Bottle No. 3 - "Aqua - mineral" is drinking water.

SLIDE number 12

DRINKING WATER is safe and harmless, although it does not have any medicinal properties. Well-purified natural waters with a relatively low salt content are used as such water. Often, such waters are cleaned to zero, and then mineralized to optimal values.

MEDICINAL - TABLE WATER - not suitable for cooking, but widely used for drinking. She has a certain therapeutic effect, but only when used correctly on the advice of a physician. Unlimited use of such water can lead to a serious disruption of the salt balance in the body and to the exacerbation of chronic diseases. Do not rely on the recommendations for use given on the label. Recommendations can only be given by a doctor and only specific person... There are special techniques, when by burning a lock of hair, your individual "mineral composition" is determined on the spectrometer. Based on this, everyone is recommended a certain style of food.

HEALING WATER - the name speaks for itself. The water is used exclusively for medicinal purposes and was previously sold only in pharmacies. To make an independent decision about the use of such water, to put it mildly, is unreasonable. Changes in the amount of mineral salts that enter the body can lead to the formation of stones and liver disease. Doctors also advise not to abuse carbonated water, especially sweet water.

SLIDE number 13

What should you drink?

Do not be afraid of water with a low salt content. Moreover, it is such water that is suitable for daily use since obviously does not introduce anything harmful into the body.

Refrain from buying if the label does not indicate where the source is, well number, place of bottling, date of bottling and guaranteed shelf life. glass bottles- 2 years, in plastic - 18 months)

It is more difficult to counterfeit a glass bottle, so counterfeit is more often poured into plastic containers.

So, today in the lesson we got acquainted with what mineral water is, studied its composition and properties.

By the next lesson, you should draw up a report on the work done.

The modernization of education carried out in the country affects primarily the subjects of the natural cycle, and, unfortunately, not in their favor. Let's try to identify emerging problems and suggest some ways to solve these problems.

The first problem is time a I am... In school education, the time devoted to the study of chemistry is steadily decreasing. Moreover, such a reduction is not experimentally justified, it contradicts different stages of a large-scale verification of the very idea of ​​modernization. For example, the highly publicized experiment on the transition to 12-year education in secondary school assumed a sparing time regime for studying chemistry: 2 hours each in the 8th, 9th and 10th grades of primary school (6 hours in total) and 2 hours each. in the 11th and 12th grades of all profiles, except for the humanitarian. For science classes, 4 hours per week were envisaged. This experiment has not yet been formally completed, but already a new experiment on pre-profile training and profile education devotes only 4 hours a week to chemistry in basic school (2 hours in 8th and 9th grades) and 1 hour in 10th grades. and 11th grades of all profiles, except for natural science, for which 3 hours a week are allocated. As an alternative to one-hour courses, an integrated course in natural science is offered, which has not yet been provided with educational and methodological support and has not been resolved with personnel, since pedagogical universities and the system of retraining of teachers do not prepare full-fledged specialists to conduct this course. It is not clear why this experiment was put into practice in the work of schools when the results of the experiment on the transition to 12-year education have not yet been summed up.

Despite this, chemistry remains a full-fledged academic subject in the school curriculum, and the requirements for it also remain quite serious. Chemistry teachers are choking with the lack of time to study it. One of the promising ways to solve this problem can be an earlier study of chemistry - from the 7th grade of basic school. However, the federal curriculum does not provide for such an opportunity. Nevertheless, in many schools of the Russian Federation, their leaders find the opportunity, due to the component of the educational institution, to highlight
1-2 hours a week to study chemistry as a propaedeutic academic discipline... There are educational and methodological kits by G.M. Chernobelskaya, A.E. Gurevich, O.S. Gabrielyan and are widely used in the practice of schools.

Some publishing houses ("Bustard", "Education", "Ventana-Graf") publish numerous collections of such courses and teaching aids for students and teachers.

The second problem - personnel... It is no secret that the country's teaching corps is aging: about a third of teachers are retirees, and only a tenth are young specialists. It is well known that the prestige of the teaching profession is steadily declining, and it is not only about low wages, but also about the organization and provision of the educational process. The national project "Education" only slightly alleviates this problem. A radical approach to its solution is required: an increase in wages by at least two times, significant financial investments in the modernization and renewal of the material and technical base of educational institutions. The staffing problem most sharply affects chemistry teachers, who may disappear altogether from the list of teaching professions. Only 4 hours of vertical load in basic school and the absence of load in general in secondary school (in the case of studying natural science in it) determine the futility of young people's orientation towards this profession. The situation is aggravated by one more circumstance. Chemistry is a special academic discipline in which, along with theoretical knowledge, experimental and computational skills and abilities are also formed. Namely, the time allotted for the educational process is sorely lacking for a chemical experiment and solving computational problems. Therefore, chemistry lessons become boring, gray, devoid of effective emotional support, which provides a bright visual chemical experiment. It is not difficult to understand why chemistry is now regarded by the majority of students as an unloved subject.

It should be emphasized that the system of supplying schools with equipment and reagents that existed in the Soviet period has been destroyed and is now just beginning to revive. However, the price level is beyond the reach of the vast majority of schools. There is a need for a government mechanism to regulate prices for training equipment and reagents or to provide subsidies to manufacturers. Numerous video materials offer some surrogate solution to the problem of a chemical experiment. However, they are only relevant when required by safety regulations. In other cases, replacing student and teacher's experiment with video clips is similar to correspondence or virtual meals.

The episodic, rather than systemic, inclusion of computational problems using formulas and equations in the process of teaching chemistry leads to a break in two interrelated aspects of the consideration of chemical objects (substances and reactions) - qualitative and quantitative. Obviously, within the framework of the time allotted for the study of the subject, a significant revision of its content is necessary. An adjustment of the standard is required to reduce the academic load of the theoretical plan (for example, exclusion from the basic school course of issues related to the electronic structure of the atom and matter, redox reactions, chemical production, chemical kinetics and some others). And vice versa, it is necessary to include questions of an applied nature that form elementary household chemical literacy, which guarantees safety when handling chemicals, materials and processes (the ability to analyze information about chemical composition food and household products on their labels, strict adherence to instructions for the use of household appliances and other industrial products).

Third problem - profile... The senior specialized school in relation to chemistry can be divided into two types:

1) schools and classes in which chemistry is a non-core discipline (humanitarian, physical and mathematical and even agrotechnological) and is studied at the rate of 1 hour per week;

2) schools and classes in which chemistry is a core discipline (natural sciences, including those with in-depth study of the subject) and is studied at the rate of 3 hours (nonsense!) Per week.

The status of a non-core discipline condemns chemistry in type 1 schools to very low student motivation to study it. It is possible, in our opinion, to increase the interest of students in chemistry by strengthening the applied nature of the content and procedural aspects of its teaching (the so-called "chemistry and life"). So, when studying polymeric materials in the course of organic chemistry, it is necessary to pay attention to the formation of the ability to read the labels of knitted products in order to proper care behind them (cleaning, washing, drying, ironing). A laboratory workshop in a chemistry course may include, for example, familiarization with mineral waters or dispersed systems. Instructions for students to conduct these labs may be as follows.

Laboratory work 1.
"Introduction to mineral waters"

Check out the labels on the bottles with mineral water (Narzan, Borjomi, Essentuki, as well as the natural mineral water of your region). What ions are included in these waters? How do you find them?

To recognize calcium ions, use, as in the case of the experience of eliminating permanent water hardness, a solution of soda. To detect carbonate ions, add an acid solution to a new portion of mineral water. What are you watching?

Write down the molecular and ionic reaction equations.

Laboratory work 2.
"Acquaintance with dispersed systems"

Prepare a small collection of dispersed system samples from suspensions, emulsions, pastes and gels available at home. Label each sample.

Swap collections with your neighbor, check out the neighbor's collection, and then distribute the samples of both collections in accordance with the classification of dispersed systems.

Check the shelf life of food, medical and cosmetic gels. What property of gels determines their shelf life?

In the classes and schools of the humanitarian profile, it is planned to strengthen the humanitarization in teaching chemistry, i.e. the use of techniques, methods and means characteristic of the humanitarian disciplines.

So, in schools and classes with in-depth study of a foreign language, reading gives a good effect chemical material in a foreign language. The teacher needs to select the appropriate material in a foreign language for the chemistry program. Since the selection of such material is rather difficult to carry out, especially in a rural school or a school in a small village, you can use the capabilities of the local library or the Internet. It will be useful to involve the students themselves in the work on the selection of chemical material in a foreign language.

In language schools, to increase motivation in the study of chemistry, you can use the interdisciplinary connections of chemistry with a foreign language. So, it is effective to use tasks to establish the English-language etymology of chemical terms (for example, symbolic designations of relative atomic and molecular masses A r and M r come from the English. “Relative”) or their evolution (for example, Greek “katalysis”, English “catalize”, Russian “catalysis”). It is with great pleasure that students in schools and classes with in-depth study of a foreign language obtain and present information about the role of chemical scientists or about the development of the chemical industry in the respective country of the target language.

In humanitarian schools, it is didactically justified to use the symbolism adopted in the Russian language to designate parts of a word in the formation of generalized knowledge of chemical nomenclature. So, the general way of forming the names of binary compounds can be presented as follows. First, a short Latin name for a more electronegative element with the suffix "id" is given, and then - the name of a less electronegative element in the genitive case and the oxidation state (s. O.) Is indicated, if it is variable (copper (I) chloride, sulfide iron (III), calcium nitride):

(-) "element-id" + (+) "element-a" (s. O., If a variable).

For example, in organic chemistry, the symbolism of the Russian language helps to form the IUPAC nomenclature. So, the general way of forming the names of saturated monohydric alcohols and saturated monobasic carboxylic acids can be reflected in the following entries:

"Alkanol" (methanol, ethanol, propanol-1),

"Alkane" acid (methane, ethanic, etc.).

In procedural terms, in the classes of the humanitarian profile, in which the majority of children study with a vivid imaginative and the world, prone to emotional experiences, a significant effect is obtained when using receiving animation... This is the endowment of objects of the inanimate chemical world (elements, substances, materials, reactions) with characteristic features and signs of the living, "humanizing" them. The general way to achieve this goal is reflected in the generalized title "Artistic Image of a Substance or Process". It should be emphasized that students are happy to write essays of this kind, thereby improving their literary written speech and assimilating the necessary chemical content.

For example, an essay by Sasha B.

Methane properties

“They don't look for good from good,” says a Russian proverb, but Methan thought differently. Surrounding his carbon atom with the quadruple beauty of four hydrogen atoms, he led a carefree, free life, and therefore was the lightest of organic gases. Nevertheless, he believed that it was the carbon atom that provided him, Methane, with such an "air" existence, and therefore he treated hydrogen atoms disrespectfully: he was rude and offended them. Unable to withstand, the hydrogen atoms left the molecule, but not all at once, but one at a time. If one atom left, then calm, well-fed (saturated) Methane turned into an irritable, adventurous particle with a free valence - into a radical. Such a radical seized whatever it hit, for example, a chlorine atom, turning into a heavy dark gas - Chloromethane. This made him even more ferocious, continued to quarrel with the other three hydrogen atoms (you can't argue with chlorine, after all, it can give back). The remaining hydrogen atoms also left, gradually being replaced by new chlorine atoms. And this happened until the carefree and light gas Methane turned into a heavy, non-combustible liquid that dissolves many other organic substances - tetrachloromethane.

If, offended, the hydrogen atoms left the carbon atom all at once (and he told them: “Well, go away! bitter radish”), Then Methane, suddenly realizing what he had lost, darkened with grief and turned into a loose black soot.

That's it!

In the classes of the physical and mathematical profile, obviously, the content and procedural aspects of teaching chemistry should be somewhat different. If in terms of the connection between chemistry and life, they coincide with its teaching in humanitarian classes, then in the selection of educational material and methodology, a different didactics should be adhered to. Some topics, especially those related to physics (the structure of the atom and matter, some aspects of physical and colloidal chemistry, electrolysis, gas laws), it is more logical to study on the basis of active forms of learning (conversation, debate, conference lessons). This allows you to significantly increase the proportion of students' independent work. This approach makes it possible to widely use interdisciplinary connections and form a single natural-scientific picture of the world.

Similarly, in the classes of the agro-technological, biological-geographical profile, this is possible through the implementation of intersubject connections with biology and physical geography. At the same time, it is perplexing to refer chemistry in the classes of these profiles to non-core disciplines. Undoubtedly, the one-hour weekly workload devoted to studying chemistry in such classes should be increased.

Q u r t a i problem - integration... The fact that in the period of modernization of education it acquires particular relevance is evidenced by the fact that an integrated course "Natural Science" is offered as an alternative to separate one-hour courses in chemistry, physics and biology. We spoke above about the premature introduction of this course. And nevertheless, the ideas of integration can be fruitfully realized in individual subjects of the natural science cycle.

First, it is intra-subject integration, for example, the academic discipline of chemistry. It is carried out on the basis of uniform laws, concepts and theories for inorganic and organic chemistry in the course of general chemistry (a unified system of classification and properties of inorganic and organic compounds, typology and patterns of reactions between organic and inorganic substances, catalysis and hydrolysis, oxidation and reduction, polymers organic and inorganic, etc.)

Secondly, it is interdisciplinary natural science integration, which allows, on a chemical basis, to combine the knowledge of physics, geography, biology and ecology into a single understanding of the natural world, i.e. to form a holistic natural-scientific picture of the world. In turn, this makes it possible for high school students to realize that without knowledge of the basics of chemistry, the perception of the world around them will be incomplete and defective. People who have not received such knowledge can unconsciously become dangerous for this world, because chemically illiterate handling of substances, materials and processes threatens with considerable troubles.

Thirdly, it is integration of chemistry with humanities: history, literature, world art culture. Such integration allows using the means of the academic subject to show the role of chemistry in the non-chemical sphere of human activity. (For example, students prepare projects "Chemical plots as the basis of works of science fiction", "Chemical errors in the media and their causes", etc.) Such integration is fully consistent with the ideas of humanization and humanitarization of teaching chemistry.

P i t a i problem - attestation... In light of the latest decisions of the State Duma and the Federation Council, the final certification of graduates of secondary educational institutions in the form of the Unified State Exam (USE) should be considered a fait accompli. Since 2009, it has been transferred to a regular mode.

A lot is said about the pros and cons of the Unified State Exam in numerous publications, which will undoubtedly be published in the future. Therefore, let us dwell on some issues of preparation and conduct of the exam in chemistry. As you know, the USE test in chemistry consists of three parts:

part A - tasks of the basic level of complexity with a choice of answers;

part B - tasks of an increased level of difficulty with a short answer;

part C - tasks of a high level of complexity with a detailed answer.

This test structure is determined by specification examination work in chemistry in the form of the exam. Nevertheless, our analysis of exam items over the past three years shows that not all items in the first part of the test correspond to the basic level of difficulty. So, is it possible to consider the task for Würz synthesis corresponding to the basic level of complexity? (“The product of the interaction of 2-bromopropane with sodium is:

1) propane; 2) hexane; 3) cyclopropane; 4) 2,3-dimethylbutane ".)

Codifier content elements in chemistry for the compilation of control measuring materials (CMMs) of the exam does not always correspond to the tasks of the examination work. For example, in the codifier, medium and acidic salts are indicated as elements of content checked by the tasks of the CMMs, and in numerous test tasks, basic O clear salts, and complex salts.

The same analysis made it possible to come to the conclusion that it is problematic to prepare graduates of such classes for the successful passing of the Unified State Exam in 3 hours a week allocated for chemistry in specialized classes. Suffice it to recall that in the pre-perestroika period, 3 hours for the study of chemistry were allotted in all schools, and the examination papers did not contain tasks of a high level of complexity, for example, on drawing up the equations of redox reactions, the properties of complex compounds, the most complex transitions. Obviously, the tasks of the second and third parts (B and C) are specialized and will cause difficulties for school graduates who studied chemistry at the rate of 3 hours a week, and are feasible only for graduates of schools and classes with in-depth study of the subject. It is also obvious that everyone will need the help of the same tutor to gain the number of points required for admission to the university.

Much has been written about the numerous mistakes or incorrect wording of the USE assignments.
And yet they are being replicated. For example, in the tasks of last year, it was proposed to choose an equation corresponding to the first stage of obtaining sulfuric acid from natural raw materials, for which four options were given: hydrogen sulfide, pyrite, sulfur dioxide, sulfur dioxide and chlorine. What is the only option a graduate should be guided by if both pyrite and hydrogen sulfide are used as raw materials?

The problem of the Unified State Exam also dictates the only correct structure for studying the sections of chemistry: in the 10th grade it is necessary to study organic chemistry, and in the 11th grade - general chemistry. This sequence is due to the fact that the course of the basic school ends with a small (10–12 hours) acquaintance with organic compounds, therefore it is necessary to make the small information on organic chemistry of the 9th grade "work" for the course of organic chemistry in the 10th grade. If you study organic chemistry a year later, in the 11th grade, it will be impossible to do this - the graduating students will not even have memories of organic chemistry from basic school. Finally, an analysis of the USE tasks shows that only a fourth of all the USE test tasks are devoted to organic chemistry, and three quarters - to general and inorganic chemistry, and therefore it is advisable to study these particular sections of chemistry in the 11th grade in order to maximally help the graduate prepare for the USE.

SIXTH PROBLEM - concentric... Moscow is already switching to universal secondary education this year. The President of the country instructed the State Duma to prepare amendments to the "Law on Education" on the transition from universal basic education to universal secondary. In this regard, the question arises about the advisability of using the concentric approach in determining the content of chemistry in basic school. If all primary school graduates continue their education in high school and therefore study organic chemistry, is it worth spending precious class time learning about organic matter in 9th grade? The solution to this problem will entail the need to change the federal component of the standard for chemistry for primary and secondary schools.

Family - informational... The desire of Russian chemistry teachers to maintain a high content level of the subject while constantly reducing the study time allotted for the study of chemistry finds expression in various forms of students' independent work (short messages in the lesson, reports, abstracts, projects, etc.). Students are required to have information competence in the subject "Chemistry". Information competence means:

Choosing a source of information (Internet, digital educational resources, media, libraries, chemical experiment, etc.);

Ability to quickly and efficiently organize work with information sources;

Receiving the information;

Analysis and processing of information;

Reasoned conclusions;

Making an informed decision on the selection of information and taking responsibility for it;

Presentation (presentation) of the result.

It is important to note that the preferences of teachers and students when choosing an information source are different. Teachers of the older generation, who have little knowledge of information technology, prefer traditional sources on a printed basis (books, magazines, newspapers), while students and young teachers, on the contrary, prefer the Internet. This contradiction is easily resolved if the teacher and students cooperate in the process of obtaining, processing and presentation of chemical information in the educational process (not only the teacher teaches chemistry students, but also the students teach the teacher to work with a computer).

The information problem is especially relevant for schools in rural areas and small settlements, divorced from well-equipped and large city libraries. Within the framework of the national project "Education", almost all schools in the Russian Federation received computers and, by decision of the government, will be connected to the Internet within 1–2 years. As a result, pupils of small and other rural schools will be able to receive a full-fledged chemical education.

We have highlighted only a few of the many problems of modern school chemistry education. The solution of most of them is possible without increasing the total teaching load of schoolchildren. We believe that numerous new-fangled academic subjects ("Moscow Studies", "Economics", "MHK", "OBZH") should be taught in the regime of compulsory elective courses, returning to traditional subjects the temporary standards worked out for decades in the Soviet school.

Laboratory work No. 1

Familiarization with the properties of mixtures and dispersed systems

Target: get dispersed systems and study their properties

Equipment: test tubes, rack *

Reagents: distilled water, gelatin solution, pieces of chalk, sulfur solution

Methodical instructions:

1. Preparation of a suspension of calcium carbonate in water.

Pour 5 ml of distilled water into 2 test tubes.

Add 1 ml of 0.5% gelatin solution to test tube No. 1.

Then add a small amount of chalk to both tubes and shake vigorously.

Place both tubes in a rack and observe the separation of the suspension.

Answer the questions:

Is the separation time the same in both tubes? What role does gelatin play? What is the dispersed phase and dispersion medium in this suspension?

2. Investigation of the properties of dispersed systems

Add 0.5-1 ml of saturated sulfur solution dropwise to 2-3 ml of distilled water. It turns out an opalescent colloidal solution of sulfur. What color does the hydrosol have?

3. Write a report:

In the course of work, display the conducted experiments and their result in the form of a table:

	Target	Experience scheme	Result
	Prepare a slurry of calcium carbonate in water
	Explore the properties of dispersed systems

Make and write down a conclusion about the work done.

Practical work No. 2

Preparation of a solution of a given concentration

Target: prepare solutions of salts of a certain concentration.

Equipment: glass, pipette, scales, glass spatula, graduated cylinder

Reagents: sugar, salt, baking soda, cold boiled water

Methodical instructions:

Prepare a solution of the substance with the specified mass fraction of the substance (data are shown in the table for ten options).

Make calculations: determine what mass of substance and water you need to take to prepare the solution indicated for your option.

option	Name	mass fraction substances	mass of solution
	salt
	baking soda
	salt
	baking soda
	salt
	baking soda

1. Weigh out the salt and place it in a glass.

2. Measure out the required volume of water with a measuring cylinder and pour it into a flask with a weighed amount of salt.

Attention! When measuring a liquid, the observer's eye should be in the same plane with the liquid level. The liquid level of transparent solutions is set along the lower meniscus.

3. Write a job report:
-specify the number of the practical work, its name, purpose, equipment and reagents used;

Draw up the calculations in the form of a task;

Show the preparation of the solution by the diagram;

Draw and write a conclusion.

Laboratory work No. 2

Properties of inorganic acids

Target: study the properties of inorganic acids using hydrochloric acid as an example

Equipment: test tubes, spatula, pipette, test tube holder, alcohol lamp *

Reagents: hydrochloric acid solution, litmus, phenolphthalein, methyl orange; zinc and copper granules, copper oxide, silver nitrate solution.

Methodical instructions:

1. Testing acid solutions with indicators:

Pour hydrochloric acid solution into three test tubes and place them in a rack.

Add a few drops of each indicator to each of the tubes: 1- methyl orange, 2- litmus, 3- phenolphthalein. Record the result.

Indicator
	neutral	alkaline
Phenolphthalein	colorless	colorless
methyl orange			Orange

2. Interaction of acids with metals:

Take two test tubes and place in 1 - zinc granule, 2 - copper granule.

3. Interaction with metal oxides:

Place copper (II) oxide powder in a test tube, add hydrochloric acid solution. Heat the tube and record the result and explain.

4. Interaction with salts:

Pour silver nitrate solution into a test tube and add hydrochloric acid solution. Record and explain the result.

5. Write a job report:

Indicate the number of the laboratory work, its name, purpose, equipment and reagents used;

Fill the table

	Experience name	Experiment scheme	Observations	Explanation of Observations	Chemical equation of the reaction

* (if technically possible) computer, OMS module

Laboratory work No. 3

"Factors Affecting the Rate of a Chemical Reaction"

Target: to reveal the dependence of the rate of a chemical reaction on various factors.

Equipment: test tubes, glasses, spatula, hot plates, flasks, measuring cylinder, stand, gas outlet tubes, scales, funnel, filter paper, glass rod *

Reagents: granules of zinc, magnesium iron, pieces of marble, saline and acetic acid; zinc dust; hydrogen peroxide, manganese (II) oxide.

Methodical instructions:

1. Dependence of the rate of a chemical reaction on the nature of substances.

Pour the hydrochloric acid solution into three test tubes. Put a magnesium granule in the first tube, a zinc granule in the second, and an iron granule in the third.

Take 2 test tubes: in 1 - pour hydrochloric acid, in 2 - acetic acid. Place an equal piece of marble in each tube. Record observations, determine which reaction is going with the greatest speed and why.

2. Dependence of the rate of chemical reaction of temperature.

Pour into two beakers the same number hydrochloric acid and cover with a glass plate. Place both glasses on the hot plate: set the temperature for the first glass to 20˚C, for the second - 40˚C. Place a zinc granule on each glass plate. Activate the devices by simultaneously dropping the zinc granules from the plates. Record observations and explain.

3. Dependence of the rate of chemical reaction on the contact area of ​​the reagents.

Build two identical installations:

Pour 3 ml of hydrochloric acid of the same concentration into the flasks, set them horizontally on a tripod, put zinc powder in the first flask (in its neck) with a spatula, and zinc granule in the second. Close the flasks with gas pipes. Simultaneously activate the instruments by rotating them vertically 90 degrees counterclockwise.

4. Dependence of the rate of a chemical reaction on the catalyst.

Pour the same amount of 3% hydrogen peroxide into two beakers. Weigh one spatula of the manganese (II) oxide catalyst. Add suspended catalyst to the first beaker. What you observe, estimate the rate of decomposition of hydrogen peroxide with and without a catalyst.

5. Write a report:

Record the conducted experiments, their results and explanations in the form of a table

	Experience name	Experiment scheme	Observations	Explanation of Observations	Chemical equation of the reaction

Formulate and write down the conclusion about the influence of each factor on the rate of a chemical reaction

* (if technically possible) computer, OMS module

Practical work No. 3

Solving experimental problems on the topic: "Metals and non-metals"

Target: learn to recognize the substances offered to you, using knowledge of their chemical properties.

Equipment: test tube rack

Reagents: solutions of sodium nitrate, sodium sulfate, sodium chloride, sodium phosphate, barium nitrate, calcium nitrate, silver nitrate and copper nitrate

Methodical instructions:

1. Recognition of non-metals:

There are solutions in four test tubes: 1 - sodium nitrate, 2 - sodium sulfate, 3 - sodium chloride, 4 - sodium phosphate, determine which of the test tubes contains each of these substances (to determine the anion, you should select the cation with which the anion will precipitate ).

	1 - sodium nitrate	2 - sodium sulfate	3 - sodium chloride	4 - sodium phosphate
Substance (identifier)
Observations
Chemical reaction

2. Recognition of metals:

There are solutions in four test tubes: 1 - barium nitrate, 2 - calcium nitrate, 3 - silver nitrate, 4 - copper nitrate, determine which of the test tubes contains each of these substances (to determine the metal cation, you should select the anion with which the cation will give sediment).

Record the results of the experiments in the reporting table:

	1 - barium nitrate	2 - calcium nitrate	3 - silver nitrate	4 - copper nitrate
Substance (identifier)
Observations
Chemical reaction

Indicate the number of the practical work, its name, purpose, equipment and reagents used;

Fill in the reporting tables

Write a conclusion about the methods of identifying metals and non-metals.

Laboratory work No. 4

"Making models of molecules of organic substances"

Target: to construct ball-and-stick and scale models of molecules of the first homologues of saturated hydrocarbons and their halogen derivatives.

Equipment: set of ball-and-stick models.

Methodical instructions.

To build models, use the parts of ready-made sets or plasticine with sticks. Balls imitating carbon atoms are usually prepared from dark-colored plasticine, balls imitating hydrogen atoms - from light colors, chlorine atoms - from green or of blue color... Sticks are used to connect the balls.

Progress:

1. Assemble the ball-and-stick model of the methane molecule. On the "carbon" atom, mark four points equidistant from each other and insert sticks into them, to which the "hydrogen" balls are attached. Place this model (it should have three points of support). Now build a scale model of the methane molecule. The balls of "hydrogen" seem to be flattened and pressed into the carbon atom.

Compare the ball-and-stick model with each other. Which model more realistically conveys the structure of the methane molecule? Please explain.

2. Assemble the ball-and-stick and scale model of the ethane molecule. Draw these models on paper in a notebook.

3. Build the ball-and-stick models of butane and isobutane. Show on a model of a butane molecule what spatial forms a molecule can assume if atoms rotate around a sigma bond. Draw several spatial forms of the butane molecule on paper.

4. Assemble the ball-and-stick models of the C5H12 isomers. draw on paper.

5. Assemble the ball-and-stick model of the CH2Cl2 dichloromethane molecule

Can this substance have isomers? Try swapping the hydrogen and chlorine atoms. What conclusion do you come to?

6. Write a report:

Indicate the number of the laboratory work, its name, purpose, equipment used;

Record the completed assignments in the form of a picture and answers to questions for each assignment

Formulate and write down the conclusion.

Practical work No. 4

Solving experimental problems on the topic: "Hydrocarbons"

Target: learn to recognize the hydrocarbons offered to you, using knowledge of their chemical properties.

Methodical instructions:

Analyze how propane, ethylene, acetylene, butadiene and benzene can be recognized based on knowledge of their chemical and physical properties

Record the analysis results in the reporting table:

			acetylene	butadiene
physical properties
Chemical properties

(indicate in the table only the most distinctive properties each of the classes of hydrocarbons)

3. Write a report and state your conclusion:

Indicate the number of the practical work, its title and purpose

Fill in the reporting table

Write a conclusion about the methods of identifying hydrocarbons.

Laboratory work No. 5

"Properties of alcohols and carboxylic acids"

Target: to study the properties of saturated monohydric alcohols, polyhydric alcohols and carboxylic acids using ethanol, glycerol and acetic acid as examples.

Equipment: test tubes, metal tongs, filter paper, porcelain cup, gas outlet tube, matches, spatula, rack, test tube rack *

Reagents: ethanol, sodium metal; copper (II) sulfate, sodium hydroxide, glycerin; acetic acid, distilled water, litmus, zinc granules, calcium oxide, copper hydroxide, marble, calcium hydroxide.

1. Properties of saturated monohydric alcohols.

Pour into two test tubes ethyl alcohol.

In 1 add distilled water and a few drops of litmus. Record observations and explain.

Place a piece of sodium into the second test tube with metal tongs, after blotting it in filter paper. Record observations and explain.

Collect the evolved gas in an empty test tube. Without turning the test tube, bring a lighted match to it. Record observations and explain.

Pour a small amount of ethyl alcohol into a porcelain cup. Use a splinter to light the alcohol in the cup. Record observations and explain.

2. Qualitative reaction to polyhydric alcohols.

Pour copper (II) sulfate solution and sodium hydroxide solution into a test tube. Record observations and explain.

Then add a small amount of glycerin. Record observations and explain.

3. Properties of saturated carboxylic acids.

Pour acetic acid into five test tubes.

In 1 add a small amount of distilled water and a few drops of litmus. Place the zinc granule in 2. Collect the evolved gas in an empty test tube and check for flammability.

Place one calcium oxide spatula in 3.

In 4, place one copper hydroxide spatula.

Place a piece of marble at 5. Pass the evolved gas through a calcium hydroxide solution.

Record the observations in each of the five tubes, write down the chemical equations and explain the observed changes.

4. Write a report according to the following plan:

Indicate the number of the laboratory work, its name, purpose, equipment and reagents used;

Record the conducted experiments, their results and explanations in the form of a table (double-page spread)

	Experience name	Experiment scheme (description of actions)	Observations	Explanation of Observations	Chemical reaction equations
saturated monohydric alcohols
polyhydric alcohols
carboxylic acids

Formulate and write down a conclusion about the properties of alcohols and carboxylic acids

* (if technically possible) computer, OMS module

Laboratory work No. 6

"Properties of fats and carbohydrates"

Target: study the properties of carbohydrates and prove the unsaturated nature of liquid fats.

Equipment: test tubes, volumetric pipette, alcohol lamp, glass rod, test tube holder *

Reagents: ammonia solution of silver oxide, glucose solution, sucrose solution, sodium hydroxide solution, copper (II) sulfate solution, vegetable oil, bromine water.

1. Properties of carbohydrates:

A) Reaction of the "silver mirror"

Pour the ammonia solution of silver oxide (I) into the test tube. Add some glucose solution with a pipette. Record observations, explain them based on the structure of the glucose molecule.

B) Interaction of glucose and sucrose with copper (II) hydroxide.

In test tube No. 1, 0.5 ml of glucose solution is poured, add 2 ml of sodium hydroxide solution.

Add 1 ml of copper (II) sulfate solution to the resulting mixture.

Gently add 1 ml of water to the resulting solution and heat on the flame of an alcohol lamp to a boil. Stop heating as soon as color change starts.

Add the sucrose solution to the copper (II) sulfate solution and shake the mixture. How did the color of the solution change? What does this indicate?

Record observations and answer the questions:

1. Why does the initially formed copper (II) hydroxide precipitate dissolve to form a clear blue solution?

2. The presence of what functional groups in glucose is this reaction caused?

3. Why does the color of the reaction mixture change from blue to orange-yellow when heated?

4. What is the yellow-red precipitate?

5. What functional group in glucose is the cause of this reaction?

6. What proves a reaction with a sucrose solution?

2. Properties of fats:

Pour 2-3 drops of vegetable oil into a test tube and add 1-2 ml of bromine water. Mix everything with a glass rod.

Record observations and explain.

3. Write a report:

Indicate the number of the laboratory work, its name, purpose, equipment and reagents used;

Make a diagram of each experiment conducted, sign your observations at each stage and the equations of chemical reactions; answer the questions.

Formulate and record the conclusion

* (if technically possible) computer, OMS module

Laboratory work No. 7

"Properties of proteins"

Target: study the properties of proteins

Equipment: test tubes, pipette, test tube holder, alcohol lamp *

Reagents: solution chicken protein, sodium hydroxide solution, copper (II) sulfate solution, concentrated nitric acid, ammonia solution, lead nitrate solution, lead acetate solution.

1. Colored "reactions of proteins"

Pour the chicken protein solution into a test tube. Add 5-6 drops of sodium hydroxide and shake the contents of the tube. Add 5-6 drops of copper (II) sulfate solution.

Record observations.

Pour the chicken protein solution into another tube and add 5-6 drops of concentrated nitric acid. Then add the ammonia solution and heat the mixture slightly. Record observations.

2. Protein denaturation

Pour the chicken egg white solution into 4 tubes.

Heat the solution in the first tube to a boil.

Add lead acetate solution dropwise to the second.

Add the lead nitrate solution to the third tube.

In the fourth, add a 2 times larger volume of organic solution (% ethanol, chloroform, acetone or ether) and mix. The formation of the precipitate can be enhanced by the addition of a few drops of saturated sodium chloride solution.

Record observations and explain.

3. Write a report:

Indicate the number of the laboratory work, its name, purpose, equipment and reagents used;

Make a diagram of each experiment conducted, sign your observations at each stage and an explanation of the phenomena that occur.

Formulate and record the conclusion

* (if technically possible) computer, OMS module

Practical work No. 5

"Solving experimental problems for the identification of organic compounds"

Target: generalize knowledge about the properties of organic substances, learn to recognize organic substances, based on knowledge of qualitative reactions for each class of substances

Equipment: test tubes, alcohol lamp, test tube holder, pipette, glass rod *

Reagents: protein solution, glucose solution, pentene - 1, glycerin, phenol, iron (III) chloride, copper hydroxide solution, ammonia solution of silver oxide, bromine solution in water, lead nitrate

1. Identification of organic compounds.

Conduct experiments, based on the analysis of which, determine in which of the test tubes each of the indicated substances is located: 1- protein solution, 2- glucose solution, 3 - pentene - 1, 4 - glycerin, 5 - phenol.

2. Record the results obtained in the form of a reporting table.

	protein solution	glucose solution	pentene - 1	glycerol
iron (III) chloride
copper hydroxide
ammonia solution of silver oxide
bromine solution in water
lead nitrate

In each cell, draw the result obtained, mark the reactions that identify each of the substances. Formulate and write down a conclusion about the methods of identifying organic substances.

* (if technically possible) computer, OMS module

Practical work No. 3. Chemistry grade 8 (to the textbook of Gabrielyan O.S.)

Soil and water analysis

Target: to study the composition of the soil and some characteristics of water samples from different sources, to master practical methods of working with substances.
Equipment : laboratory rack, rack for test tubes, test tube with stopper, test tube, magnifying glass, filter paper, funnel, glass plate, glass rod, tweezers, pipette, transparent flat-bottomed glass cylinder 2-2.5 cm in diameter, 30-35 cm high (or 250 ml graduated cylinder without plastic support), conical flask with stopper, heating device, matches, indicator paper (blue and red), sheet with printed text.
Reagents: samples of soil, water from the reservoir, tap water, distilled water.

Experience 1.
Mechanical analysis of the soil.

Work order:

Place soil in a test tube (soil column 2-3 cm high).
Add distilled water, the volume of which should be 3 times the volume of the soil.
Close the tube with a stopper and shake thoroughly for 1-2 minutes.
We observe with a magnifying glass the sedimentation of soil particles and the structure of the sediment.
Observed phenomena: substances contained in the soil settle at different rates. After a while, the contents will stratify: heavy sand will settle at the bottom, above there will be a cloudy layer of suspended clay particles, even higher - a layer of water, on its surface - mechanical impurities (for example, sawdust).
Output: soil is a mixture of various substances.

Experience 2.
Obtaining a soil solution and experiments with it.

Work order:

1. Prepare the paper filter, insert it into the funnel fixed in the tripod ring.
We put a clean dry test tube under the funnel and filter the mixture of soil and water obtained in the first experiment.
Observed phenomena: the soil remains on the filter, and the filtrate is collected in the test tube - this is a soil extract (soil solution).
Output: soil contains water-insoluble substances

2. Place a few drops of this solution on a glass plate.
Using tweezers, hold the plate over the burner until the water evaporates.
Observed phenomena: water evaporates, and crystals of substances previously contained in the soil remain on the plate.
Output: soil contains water-soluble substances.

3. Apply the soil solution with a glass rod on two litmus papers (red and blue).
Observed phenomena:
a) the blue indicator paper changes color to red.
Output: the soil is acidic.
a) The red indicator paper changes color to blue.
Output: the soil is alkaline.

Experience 3.
Determination of water transparency.

Work order:

We put a transparent flat-bottomed glass cylinder with a diameter of 2-2.5 cm, a height of 30-35 cm (or a measuring cylinder of 250 ml without a plastic stand) on a sheet with printed text.
Pour distilled water into the cylinder until the font is visible through the water.
We measure the height of the water column with a ruler.
Observed phenomena: ... cm - the height of the water column.
We carry out the experiment with water from a reservoir in a similar way.
Observed phenomena: ... cm - the height of the water column.
Output: distilled water is more transparent than water from a reservoir.

Experience 4.
Determination of the intensity of the smell of water.

Work order:

Fill the conical flask to 2/3 of its volume with the test water, close it tightly with a stopper and shake it vigorously.
We open the flask and note the nature and intensity of the smell using the table of the textbook.
Observed phenomena: .... (for example, a distinct smell - unpleasant, intensity - 4 points).
Output: ... (for example, bad smell may be a reason for refusing to drink).

General conclusion on work : in the course of this practical work, the composition of the soil was studied, the transparency and intensity of the smell of water were investigated, the practical methods of working with substances were improved.