Several tens of thousands of the most important chemicals have tightly entered our lives, clothing and footwear, supplying our body with useful elements, providing us with optimal conditions for life. Oils, alkalis, acids, gases, mineral fertilizers, paints, plastics are only a small part of the products created on the basis of chemical elements.

Did not know?

When we wake up in the morning, we wash our faces and brush our teeth. Soap, toothpaste, shampoo, lotions, creams - products created on the basis of chemistry. We brew tea, dip a piece of lemon into a glass - and observe how the liquid becomes lighter. Before our eyes, a chemical reaction is taking place - an acid-base interaction of several products. Bathroom and kitchen - each, in its own way, a mini-laboratory of a house or apartment, where something is stored in a container or vial. What substance, we recognize their name from the label: salt, soda, whiteness, etc.

Especially a lot of chemical processes occur in the kitchen during the cooking period. Frying pans and pans successfully replace flasks and retorts here, and each new product sent to them carries out its own separate chemical reaction, interacting with the composition located there. Further, a person, using the dishes prepared by him, starts the mechanism of digestion of food. This is also And so it is in everything. Our whole life is predetermined by the elements from Mendeleev's periodic table.

open table

Initially, the table created by Dmitry Ivanovich consisted of 63 elements. That's how many of them were open by that time. The scientist understood that he classified a far from complete list of elements existing and discovered in different years by his predecessors in nature. And he turned out to be right. More than a hundred years later, his table already consisted of 103 items, by the beginning of the 2000s - from 109, and discoveries continue. Scientists around the world are struggling to calculate new elements, based on the basis - a table created by a Russian scientist.

Mendeleev's periodic law is the basis of chemistry. Interactions among themselves of atoms of these or those elements have generated in the nature the basic substances. Those, in turn, are previously unknown and more complex derivatives of them. All the names of substances that exist today come from elements that have entered into a relationship with each other in the process of chemical reactions. Molecules of substances reflect the composition of these elements in them, as well as the number of atoms.

Each element has its own letter symbol

In the periodic table, the name of the elements is given both in literal and symbolic terms. Some we pronounce, others we use when writing formulas. Write down the names of the substances separately and look at a number of their symbols. It shows what elements the product consists of, how many atoms of one or another constituent could be synthesized in the process of a chemical reaction by each specific substance. Everything is quite simple and clear, thanks to the presence of symbols.

The basis of the symbolic expression of the elements was the initial, and, in most cases, one of the subsequent letters from the Latin name of the element. The system was proposed in the early 19th century by Berzelius, a Swedish chemist. One letter today expresses the names of two dozen elements. The rest are two-letter. Examples of such names: copper - Cu (cuprum), iron - Fe (ferrum), magnesium - Mg (magnium) and so on. In the name of substances, the reaction products of certain elements are given, and in the formulas - their symbolic series.

The product is safe and not very

There is a lot more chemistry around us than the average person can imagine. Not doing science professionally, we still have to deal with it in our daily lives. Everything that is on our table is made up of chemical elements. Even the human body is made up of dozens of chemicals.

The names of chemicals that exist in nature can be divided into two groups: used in everyday life or not. Complex and dangerous salts, acids, ether compounds are highly specific and used exclusively in professional activities. They require care and precision in their use, and in some cases, special permission. Substances that are indispensable in everyday life are less harmless, but their improper use can lead to serious consequences. From this we can conclude that harmless chemistry does not exist. We will analyze the main substances with which human life is associated.

Biopolymer as a building material of the body

The main fundamental component of the body is protein - a polymer consisting of amino acids and water. It is responsible for the formation of cells, hormonal and immune systems, muscle mass, bones, ligaments, internal organs. The human body consists of more than one billion cells, and each needs protein or, as it is also called, protein. Based on the above, give the names of substances that are more indispensable for a living organism. The basis of the body is the cell, the basis of the cell is the protein. No other is given. The lack of protein, as well as its excess, leads to disruption of all vital functions of the body.

In the construction of proteins, the order of creating macromolecules by peptide bonds is involved. Those, in turn, arise as a result of the interaction of substances COOH - carboxyl and NH 2 - amino groups. The most famous of the proteins is collagen. It belongs to the class of fibrillar proteins. The very first, the structure of which was established, is insulin. Even for a person far from chemistry, these names speak volumes. But not everyone knows that these substances are proteins.

Essential amino acids

A protein cell consists of amino acids - the name of substances that have a side chain in the structure of molecules. They are formed by: C - carbon, N - nitrogen, O - oxygen and H - hydrogen. Of the twenty standard amino acids, nine enter the cells exclusively with food. The rest are synthesized by the body in the process of interaction of various compounds. With age or in the presence of diseases, the list of nine essential amino acids expands significantly and is replenished with conditionally essential ones.

In total, more than five hundred different amino acids are known. They are classified in many ways, one of which divides them into two groups: proteinogenic and non-proteinogenic. Some of them play an irreplaceable role in the functioning of the body, not associated with the formation of protein. The names of organic substances in these groups, which are key: glutamate, glycine, carnitine. The latter serves as a transporter of lipids throughout the body.

Fats: both simple and difficult

All fat-like substances in the body we are accustomed to call lipids or fats. Their main physical property is insolubility in water. However, in interaction with other substances, such as benzene, alcohol, chloroform and others, these organic compounds break down quite easily. The main chemical difference between fats is similar properties, but different structures. In the life of a living organism, these substances are responsible for its energy. So, one gram of lipids is able to release about forty kJ.

A large number of substances included in the molecules of fats do not allow their convenient and accessible classification. The main thing that unites them is their attitude to the hydrolysis process. In this respect, fats are saponifiable and unsaponifiable. The names of the substances that create the first group are divided into simple and complex lipids. Simple include some types of wax, choresterol esters. The second - sphingolipids, phospholipids and a number of other substances.

Carbohydrates as the third type of nutrient

The third type of basic nutrients of a living cell, along with proteins and fats, is carbohydrates. These are organic compounds consisting of H (hydrogen), O (oxygen) and C (carbon). and their functions are similar to those of fats. They are also sources of energy for the body, but unlike lipids, they mainly get there with food of plant origin. The exception is milk.

Carbohydrates are divided into polysaccharides, monosaccharides and oligosaccharides. Some do not dissolve in water, others do the opposite. The following are the names of insoluble substances. These include such complex carbohydrates from the group of polysaccharides as starch and cellulose. Their splitting into simpler substances occurs under the influence of juices secreted by the digestive system.

Useful substances of the other two groups are found in berries and fruits in the form of water-soluble sugars that are perfectly absorbed by the body. Oligosaccharides - lactose and sucrose, monosaccharides - fructose and glucose.

glucose and fiber

Substance names such as glucose and fiber are common in everyday life. Both are carbohydrates. One of the monosaccharides contained in the blood of any living organism and the juice of plants. The second is from polysaccharides, which is responsible for the digestion process; in other functions, fiber is rarely used, but it is also an indispensable substance. Their structure and synthesis are quite complex. But it is enough for a person to know the basic functions taken in the life of the body in order not to neglect their use.

Glucose provides cells with a substance such as grape sugar, which gives energy for their rhythmic, uninterrupted functioning. About 70 percent of glucose enters the cells with food, the remaining thirty - the body produces on its own. The human brain is in dire need of glucose of food origin, since this organ is not capable of synthesizing glucose on its own. In honey, it is found in the greatest quantity.

Not so simple ascorbic

Familiar to everyone since childhood, the source of vitamin C is a complex chemical substance consisting of hydrogen and oxygen atoms. Their interaction with other elements can even lead to the creation of salts - it is enough to change just one atom in the compound. In this case, the name and class of the substance will change. Experiments carried out with ascorbic acid revealed its indispensable properties in the function of restoring human skin.

In addition, it strengthens the immune system of the skin, helps to resist the negative effects of the atmosphere. It has anti-aging, whitening properties, prevents aging, neutralizes free radicals. Contained in citrus fruits, bell peppers, medicinal herbs, strawberries. About a hundred milligrams of ascorbic acid - the optimal daily dose - can be obtained with rose hips, sea buckthorn, and kiwi.

Substances around us

We are convinced that our whole life is chemistry, since a person himself entirely consists of its elements. Food, footwear and clothing, hygiene products - only a small fraction of where we meet the fruits of science in everyday life. We know the purpose of many elements and use them for our own benefit. In a rare house you will not find boric acid, or slaked lime, as we call it, or calcium hydroxide, as it is known to science. Copper sulphate is widely used by man - copper sulfate. The name of the substance comes from the name of its main component.

Sodium bicarbonate is a common soda in everyday life. This new acid is acetic acid. And so with any or animal origin. All of them are composed of compounds of chemical elements. Far from everyone can explain their molecular structure, it is enough to know the name, purpose of the substance and use it correctly.

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Attention! The slide preview is for informational purposes only and may not represent the full extent of the presentation. If you are interested in this work, please download the full version.

Target: to show the close connection of chemistry with our daily life.

Equipment: multimedia projector; three types of soap - household, toilet, liquid; two types of washing powder - for cotton and woolen fabrics; phenolphthalein; soda; acetic acid solution; citric acid crystalline; flour; water; test tubes; chemical glasses; putty knife.

PROGRESS OF THE EVENT

(Slide 2)

Teacher. In the beginning was the word. And the word was God. For seven days and nights, the creator created the material world, which consists of matter. And the substance is the object of study of the science of CHEMISTRY.

(Slide 3)

– So, let's be fascinated by this divine science together, and make sure that our entire environment is chemicals. And you and I, our body and even our feelings are also chemistry.
Let's start from the very beginning. Here the baby is born. (Slide 4) With his first cry, the lungs expand, the baby takes its first breath. And this process accompanies us all our lives.

Questions to the audience:

What kind of gas do we need? (Oxygen)

What is the name of the substance that carries oxygen? (Hemoglobin)

Let's admire this wonderful molecule together. (Slide 5) Oxygen, having joined, to the iron ion located in the middle of hemoglobin, as in a carriage, travels to all organs of our body. Our tissues are filled with life-giving oxygen, thanks to which oxidation processes take place.

- And now another moment. Tell me, have you experienced stress? Certainly! I believe stress is familiar to many.

Question to the audience:

– Do you know what hormone is produced in this case? (Adrenalin)

- Did you feel nervous today?

- Of course, at school you can’t do without excitement! And again you have an adrenaline rush. (Slide 6) Wise nature created adrenaline for action. Therefore, when adrenaline is released, a person needs to actively move, run, jump, wave his arms. What are we going to do now. We got up. We raised our hands, we actively shake our hands. Let's stomp our feet at the same time.

- Well done! All accumulated adrenaline worked out.

– It turns out that resistance to stress depends on the protein to which adrenaline is attached. If the protein molecule is large, the person is resistant to stress; if it is small, the resistance to stress is low. Let's admire the wonderful structure of the protein molecule. (Slide 7) Let us admire the wise nature that created such beauty.

Question to the audience:

What determines the structure of a protein? Where is hereditary information encrypted? (DNA)

– Of course, in the DNA molecule. Let's look at the structure of DNA. (Slide 8) Look what a beauty! On the left is a top view, on the right is a double helix consisting of two complementary strands. No wonder they are so named, one chain compliments the other. The full name of DNA is deoxyribonucleic acid. Sounds like a song!

Let's do a thought experiment - let's go to our house. We are always welcome at home.

Question to the audience:

- Who meets you first at the door? What are your feelings about this?

- Amazing! All of us are waiting at home for moms and dads, grandparents, cats and dogs, hamsters and parrots. And we are happy to meet them. (Slide 9)

- Now imagine - in front of you is a plate of dumplings seasoned with sour cream. Or a pie with a ruddy crust is smoking on the table. The house is filled with amazing aroma. You bring the desired piece to your mouth. What do you experience?
You would not have experienced all this bliss if the hormone of joy, serotonin, had not been formed in the body. Admire the hero of the occasion! (Slide 10) Good! Let's work it out here and now. No, unfortunately you won't be holding a hefty piece of cake in your hand right now. You don't pet your beloved pet. We will do it easier - remember childhood. Each of us, as a child, smiled and laughed fervently about 360 times a day. Smile, find bumps of joy on your face next to your cheekbones. Rub them vigorously with your fingertips. Look at your neighbors on the left and right, give them your smile! This is how serotonin is produced!

So, we are at home. First of all, we will visit the home laboratory called the bathroom. (Slide 11) We wash our hands, at the same time without wasting time, turn on the washing machine. What soap to choose? What kind of powder? Five chemists are needed to conduct the experiment. With them, we will check the alkaline properties of three types of soap - laundry, toilet, liquid and two types of powder - for wool and for cotton fabrics. (There are samples of the above detergents in five test tubes. A few milliliters of water are poured into each, shaken. Then a drop of phenolphthalein solution is dropped into the solutions, the intensity of crimson staining is observed and conclusions are drawn.)

Conclusions. The brightest color in a solution of laundry soap, the medium is highly alkaline, therefore, this soap must be used for washing heavily soiled items. The toilet soap solution also changed the color of the indicator - we use it to wash dirty hands and body. But liquid soap can be used often, since its solution did not change the color of the indicator, the medium is neutral.
The most alkaline environment in a solution of laundry detergent for cotton fabrics, therefore, this type of detergent should be used to wash items made from fabrics that can withstand an aggressive environment. In another form of powder, the solution of phenolphthalein only turned pink, that is, it is suitable for washing products made from natural silk and woolen fabrics.

- We pass to the kitchen - the main home laboratory. Here the main sacraments of preparation take place. What is the main laboratory of the house equipped with? (Slide 12)
Meet "Hot Majesty" - a stove.

Questions to the audience:

- What is the plate for? What is burning in it?

- And now, please, someone who wishes to write down the reaction of methane combustion on the board, and compare it with the recording on the screen.

- Let's draw conclusions. Methane reacts with oxygen to release carbon dioxide and water vapor. Therefore, when igniting the burners, it is necessary to open the window. And why are we starting a combustion reaction? Of course, we need the energy released as a result of the reaction. Therefore, the reaction is written in thermochemical form, at the end of the equation +Q, which means the release of heat - the reaction is exothermic.

- Next in line is Frosty Majesty - a refrigerator.

Question to the audience:

What is a refrigerator for?

- You are right, it is necessary to slow down the processes of food spoilage - the reactions of oxidation and decomposition. The refrigerator personifies the most difficult section of chemistry - chemical kinetics. Let's treat the "Frosty Majesty" with respect.

- Let's move on to the "Highnesses" - cabinets. What is not here - spoons, ladles, pots, pans, cereals, flour, salt, sugar, spices and much more tasty and interesting. We will cook a pie from shortcrust pastry, and chemically competently. In cookbooks, it is recommended to add soda quenched with vinegar to prepare the dough.

Question to the audience:

- What is the purpose of adding soda with vinegar to the dough?

- It is true that the cake was magnificent. Now look at this reaction. (Demonstration of the interaction of soda with acetic acid). We observe "boiling" due to the release of carbon dioxide. So, the bulk of carbon dioxide has escaped into the atmosphere, there is not much gas left to raise the test. Therefore, we do not extinguish soda with vinegar, but add soda and dry crystalline citric acid to the flour. Knead the dough by adding the necessary ingredients.

(Demonstration. In a deep glass, mix soda, crystalline citric acid, flour, add water. A slow rise of lush dough is observed. In another glass, mix flour with water, add soda quenched with vinegar there. In this case, the dough rises much less and quickly settles. )

– You and I made sure that pies also need to be prepared chemically competently. Carbon dioxide must be released during the baking process - the result is a fluffy cake, just like ours! (Slide 13)

“I think I convinced you that chemistry is the poem of matter!” (Slide 14)

In the previous chapter, it was said that not only atoms of one chemical element, but also atoms of different elements can form bonds with each other. Substances formed by atoms of one chemical element are called simple substances, and substances formed by atoms of different chemical elements are called complex substances. Some simple substances have a molecular structure, i.e. are made up of molecules. For example, substances such as oxygen, nitrogen, hydrogen, fluorine, chlorine, bromine, and iodine have a molecular structure. Each of these substances is formed by diatomic molecules, so their formulas can be written as O 2, N 2, H 2, F 2, Cl 2, Br 2 and I 2, respectively. As you can see, simple substances can have the same name with the elements that form them. Therefore, one should clearly distinguish between situations when it comes to a chemical element, and when it is about a simple substance.

Often, simple substances have not a molecular, but an atomic structure. In such substances, atoms can form various types of bonds with each other, which will be discussed in detail a little later. Substances of this structure are all metals, for example, iron, copper, nickel, as well as some non-metals - diamond, silicon, graphite, etc. For these substances, not only the name of the chemical element coincides with the name of the substance formed by it, but the formula of the substance and the designation of the chemical element are also identical. For example, the chemical elements iron, copper and silicon, which have the designations Fe, Cu and Si, form simple substances, the formulas of which are Fe, Cu and Si, respectively. There is also a small group of simple substances, consisting of disparate atoms, not connected in any way. Such substances are gases, which are called, due to their extremely low chemical activity, noble. These include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn).

Since there are only about 500 known simple substances, it follows logically that many chemical elements are characterized by a phenomenon called allotropy.

Allotropy is the phenomenon when one chemical element can form several simple substances. Different chemicals formed by one chemical element are called allotropic modifications or allotropes.

So, for example, the chemical element oxygen can form two simple substances, one of which has the name of the chemical element - oxygen. Oxygen as a substance consists of diatomic molecules, i.e. its formula is O 2 . It is this compound that is part of the vital air we need. Another allotropic modification of oxygen is the triatomic gas ozone, whose formula is O 3 . Despite the fact that both ozone and oxygen are formed by the same chemical element, their chemical behavior is very different: ozone is much more active than oxygen in reactions with the same substances. In addition, these substances differ from each other in physical properties, at least due to the fact that the molecular weight of ozone is 1.5 times greater than that of oxygen. This leads to the fact that its density in the gaseous state is also 1.5 times greater.

Many chemical elements tend to form allotropic modifications that differ from each other in the structural features of the crystal lattice. So, for example, in Figure 5, you can see schematic representations of fragments of the crystal lattices of diamond and graphite, which are allotropic modifications of carbon.

Figure 5. Fragments of crystal lattices of diamond (a) and graphite (b)

In addition, carbon can also have a molecular structure: such a structure is observed in such a type of substances as fullerenes. Substances of this type are formed by spherical carbon molecules. Figure 6 shows 3D models of the c60 fullerene molecule and a soccer ball for comparison. Note their interesting resemblance.

Figure 6. C60 fullerene molecule (a) and soccer ball (b)

Compounds are substances that are made up of atoms of different elements. They, like simple substances, can have a molecular and non-molecular structure. The non-molecular type of structure of complex substances can be more diverse than that of simple ones. Any complex chemical substances can be obtained either by direct interaction of simple substances, or by a sequence of their interactions with each other. It is important to be aware of one fact, which is that the properties of complex substances, both physical and chemical, are very different from the properties of the simple substances from which they are derived. For example, table salt, which has a NaCl forum and is colorless transparent crystals, can be obtained by reacting sodium, which is a metal with properties characteristic of metals (luster and electrical conductivity), with chlorine Cl 2, a yellow-green gas.

Sulfuric acid H 2 SO 4 can be formed by a series of successive transformations from simple substances - hydrogen H 2 , sulfur S and oxygen O 2 . Hydrogen is a gas lighter than air that forms explosive mixtures with air, sulfur is a yellow solid that can burn, and oxygen is a gas slightly heavier than air in which many substances can burn. Sulfuric acid, which can be obtained from these simple substances, is a heavy oily liquid with strong water-removing properties, due to which it chars many substances of organic origin.

Obviously, in addition to individual chemicals, there are also mixtures of them. It is mainly mixtures of various substances that form the world around us: metal alloys, food, drinks, various materials that make up the objects around us.

For example, the air we breathe consists mainly of nitrogen N 2 (78%), oxygen that is vital for us (21%), while the remaining 1% is impurities of other gases (carbon dioxide, noble gases, etc.).

Mixtures of substances are divided into homogeneous and heterogeneous. Homogeneous mixtures are those mixtures that do not have phase boundaries. Homogeneous mixtures are a mixture of alcohol and water, metal alloys, a solution of salt and sugar in water, mixtures of gases, etc. Heterogeneous mixtures are those mixtures that have a phase boundary. Mixtures of this type include a mixture of sand and water, sugar and salt, a mixture of oil and water, etc.

The substances that make up mixtures are called components.

Mixtures of simple substances, unlike chemical compounds that can be obtained from these simple substances, retain the properties of each component.

The environment is material. Matter is of two types: substance and field. The object of chemistry is a substance (including the influence on the substance of various fields - sound, magnetic, electromagnetic, etc.)

Substance - everything that has a rest mass (i.e., it is characterized by the presence of mass when it is not moving). So, although the rest mass of one electron (the mass of a non-moving electron) is very small - about 10 -27 g, but even one electron is a substance.

Matter exists in three states of aggregation - gaseous, liquid and solid. There is another state of matter - plasma (for example, there is plasma in thunderstorm and ball lightning), but the chemistry of plasma is almost not considered in the school course.

Substances can be pure, very pure (necessary, for example, to create fiber optics), can contain noticeable amounts of impurities, can be mixtures.

All substances are made up of tiny particles called atoms. Substances made up of atoms of the same type(from atoms of one element), called simple(for example, charcoal, oxygen, nitrogen, silver, etc.). Substances that contain interconnected atoms of different elements are called complex.

If a substance (for example, in air) contains two or more simple substances, and their atoms are not interconnected, then it is called not a complex, but a mixture of simple substances. The number of simple substances is relatively small (about five hundred), while the number of complex substances is enormous. To date, tens of millions of different complex substances are known.

Chemical transformations

Substances are able to interact with each other, and new substances arise. Such transformations are called chemical. For example, a simple substance coal interacts (chemists say - reacts) with another simple substance - oxygen, resulting in the formation of a complex substance - carbon dioxide, in which the carbon and oxygen atoms are interconnected. Such transformations of one substance into another are called chemical. Chemical transformations are chemical reactions. So, when sugar is heated in air, a complex sweet substance - sucrose (of which sugar is composed) - turns into a simple substance - coal and a complex substance - water.

Chemistry is the study of the transformation of one substance into another. The task of chemistry is to find out with which substances this or that substance can interact (react) under given conditions, what is formed in this case. In addition, it is important to find out under what conditions this or that transformation can proceed and the desired substance can be obtained.

Physical properties of substances

Each substance is characterized by a combination of physical and chemical properties. Physical properties are properties that can be characterized using physical instruments.. For example, using a thermometer, you can determine the melting and boiling points of water. Physical methods can characterize the ability of a substance to conduct an electric current, determine the density of a substance, its hardness, etc. During physical processes, substances remain unchanged in composition.

The physical properties of substances are divided into countable (those that can be characterized using certain physical devices by a number, for example, indicating density, melting and boiling points, solubility in water, etc.) and innumerable (those that cannot be characterized by a number or very difficult such as color, smell, taste, etc.).

Chemical properties of substances

The chemical properties of a substance are a set of information about what other substances and under what conditions a given substance enters into chemical interactions.. The most important task of chemistry is to identify the chemical properties of substances.

Chemical transformations involve the smallest particles of substances - atoms. During chemical transformations, other substances are formed from some substances, and the original substances disappear, and instead of them new substances (reaction products) are formed. BUT atoms at all chemical transformations are preserved. Their rearrangement occurs, during chemical transformations, old bonds between atoms are destroyed and new bonds arise.

Chemical element

The number of different substances is huge (and each of them has its own set of physical and chemical properties). There are relatively few atoms in the material world around us, differing from each other in their most important characteristics - about a hundred. Each type of atom has its own chemical element. A chemical element is a collection of atoms with the same or similar characteristics.. There are about 90 different chemical elements found in nature. To date, physicists have learned how to create new types of atoms that are absent on Earth. Such atoms (and, accordingly, such chemical elements) are called artificial (in English - man-made elements). More than two dozen artificially obtained elements have been synthesized to date.

Each element has a Latin name and a one- or two-letter symbol. There are no clear rules for the pronunciation of the symbols of chemical elements in the Russian-language chemical literature. Some pronounce it like this: they call the element in Russian (symbols of sodium, magnesium, etc.), others - in Latin letters (symbols of carbon, phosphorus, sulfur), others - how the name of the element sounds in Latin (iron, silver, gold, mercury ). It is customary to pronounce the symbol of the hydrogen element H in the same way as this letter is pronounced in French.

A comparison of the most important characteristics of chemical elements and simple substances is given in the table below. Several simple substances can correspond to one element (the phenomenon of allotropy: carbon, oxygen, etc.), or maybe one (argon and other inert gases).

Abstract: Elective course in chemistry for 9th grade students. Substances around us

Elective course in chemistry for 9th grade students.

Substances around us.

One of the directions of modernization of modern education is the transition to specialized education in high school. The introduction of pre-profile training through the organization of elective courses is a necessary condition for creating an educational space for the basic school.

This manual presents the program of the elective course in chemistry "Substances around us", intended for students in grade 9.

The course provides information that allows us to understand the processes in the world around us, information about the unusual properties of known substances, the problem of ecology, and a chemical workshop are touched upon.

The course is aimed at expanding and deepening knowledge of chemistry, at developing general educational skills, broadening one's horizons.

This program is built according to the general scheme. The explanatory note describes the features of the course, specifies its goals and objectives. Lesson planning provided. The requirements for the level of achievements of the student at the end of the course are formulated, a list of literature and multimedia teaching aids recommended for the teacher is proposed. The application contains an example of a summary of the lesson, practical work.

Explanatory note.

The course is non-systematic and can be studied in parallel with the traditional school chemistry course (any program). It is based on the knowledge gained in the study of the basic course of chemistry and does not require knowledge of theoretical issues that go beyond the standard.

Course Objectives:

Orientation of students to continue education in the classes of the natural science profile, the expansion and deepening of knowledge in chemistry, the expansion of horizons, the formation of environmental thinking.

Course objectives:

• Development and strengthening of interest in the subject
• Disclosure of the chemistry of the surrounding world
• Familiarize students with the effects of chemicals on the human body
• Deepening, expanding and systematizing knowledge about the structure, properties, use of substances
• Improving the skills of handling chemical devices, utensils, substances; solving experimental problems
• To form an idea of ​​​​professions related to chemistry

Introduction (1 hour). Familiarize students with the goals and objectives of this course. Brief tour of the program.

Simple substances. (3 hours)

Oxygen, ozone, nitrogen. Obtaining, application, circulation in nature, biological role. Carbon, its allotropic modifications: diamond, graphite, fullerenes. Air. Ecology of the air basin. inert gases.

Water. (8 ocloc'k)

Composition. The structure of the water molecule. Water properties. Isotopes of hydrogen. Heavy water. The role of heavy water. The biological role of heavy water.

Water anomalies: high boiling point, freezing expansion, ice, change in density with temperature. Living water.

Water in living organisms. The biological role of water and its functions in the human body, animals and plants.

Water is a universal solvent. Solubility curve. Ways of expressing the concentration of a solute: percentage, molar, normal. Preparation of solutions with a given concentration. Hardness of water and ways to eliminate it.

Oxides and their role (7 hours)

Carbon monoxide (IV). Obtaining carbon dioxide, its properties and application. physiological significance. The phenomenon of coughing and yawning. Harm of smoking, composition of cigarettes. The chemical composition of plants. Photosynthesis. Essence, products of photosynthesis: glucose, starch, oxygen.

Carbon monoxide (II), production methods, properties. Physiological activity of carbon monoxide. Carbon monoxide (II) as a chemical raw material in organic synthesis. Silicon (IV) oxide. Prevalence in nature, biological significance of silicon: epithelial cells, elastin. The use of silicon oxide (IV). nitrogen oxides.

Foundations and their role (3 hours)

Foundations in life. Slaked lime, application. Alkalis: sodium hydroxide, potassium hydroxide. Soap. Hydrogen index of the solution medium. Acid-base balance.

Acids and their role (4 hours)

Hydrochloric acid. Discovery of hydrochloric acid. Hydrochloric acid as a component of the gastric juice of humans and mammals. Synthesis of hydrochloric acid. Sulfur compounds: hydrogen sulfide, sulfuric acid. Formation in nature, effect on organisms, application. Qualitative reactions to hydrochloric, sulfuric, hydrosulfide acids.

Acetic acid. Acetic acid as one of the drugs in ancient times. Receiving now. Application. Preparation of table vinegar from vinegar essence.

Salts and their biological role (5 hours)

Sodium chloride. Table salt in the history of the development of civilizations. Being in nature, prey. The biological significance of table salt. Baking soda, obtaining, application. Glauber's salt, discovery, significance in medicine. Calcium carbonate. Finding in nature, extraction, application.

Salt hydrolysis. Qualitative reactions to salts.

Substances in the medicine cabinet (2 hours)

Activated carbon. coal adsorption.

Iodine. History of discovery, structure, physical and chemical properties, application.

Hydrogen peroxide. Structure, properties, obtaining. Antimicrobial and bleaching action of hydrogen peroxide.

Potassium permanganate. Composition, properties, application in medicine.

Vitamins. Types, the need for vitamins.

Mercury. Mercury vapor toxicity.

The danger of self-medication.

requirements for learning outcomes.

After studying the elective course "Substances around us", students should:

Know the structure and properties of simple and complex substances that surround us in nature and everyday life, to know their biological significance, the main methods of their production, processing, human use; know the rules of work and handling of laboratory equipment;

Be able to to make the simplest measurements (mass, density, volume); prepare solutions with a given mass fraction of the solute; determine the percentage concentration of solutions of acids, alkalis, salts according to tabular values ​​of densities; compare, highlight the main thing, draw conclusions and generalizations; organize their educational work, use additional literature, use ICT in the learning process; work with laboratory equipment; draw up equations of chemical reactions and make calculations on them (amount of substance, mass, volume); use the acquired knowledge in everyday life and in practical activities.

Planning lessons for the elective course "Substances around us".

Lesson topic	Issues under study
1. Introduction
2. Simple substances. Oxygen, ozone, nitrogen.	Obtaining, application, circulation in nature, biological role.
3. Carbon.	Allotropic modifications of carbon: diamond, graphite, carbine, fullerenes.
4. Air.	Air composition. Inert gases, history of discovery, application. Sources of air pollution, cleaning methods.
5-6. Water. The composition of water.	The composition of the water molecule, structure, properties. Isotopes of hydrogen. Heavy water. The biological role of heavy water.
7. Water anomalies.	High boiling point, expansion on freezing, ice, change in density with temperature. Living water.
8. Water in living organisms.	The biological role of water and its functions in the body of animals, humans and plants.
9-10. Water as a solvent.	aqueous solutions. Solubility curve. Ways of expressing the concentration of a solute. Percent concentration of solutions. Molar concentration of solutions. Normal concentration.
11. Practical work. Preparation of solutions of a given concentration.
12. Water hardness and ways to eliminate it.	Practical work. Ways to eliminate water hardness.
13. Oxides and their role. Carbon monoxide (IV).	Obtaining, properties and application of carbon dioxide.
14. Harm of smoking.	Composition of a cigarette. The phenomenon of coughing and yawning. Physiological significance of carbon dioxide.
15. Photosynthesis.	The chemical composition of plants. The essence of the process of photosynthesis. Products of photosynthesis: glucose, starch, oxygen.
16. Practical work. Obtaining and properties of carbon dioxide.
17. Carbon monoxide (II).	Methods for obtaining, properties, physiological activity of carbon monoxide. Carbon monoxide (II) as a chemical raw material in organic synthesis.
18. Silicon oxide (IV).	Distribution in nature, properties, application. Biological significance of silicon, epithelial cells, elastin.
19. Nitrogen oxides.	Nitrous oxide, nitric oxide, nitrous anhydride, nitrogen dioxide, nitric anhydride. History of discovery, composition, application.
20. Foundations and their role. Foundations in life.	Slaked lime, production, application. Alkalis: potassium hydroxide, sodium hydroxide. Soap.
21. Hydrogen index of the solution medium.	pH of the solution medium. Acid-base balance.
22. Practical work. Determination of the pH of some household solutions.
23. Acids and their role. Hydrochloric acid.	variety of acids. Hydrochloric acid discovery. Hydrochloric acid as a component of the gastric juice of humans and mammals. Synthesis of hydrochloric acid.
24. Sulfur compounds.	Hydrogen sulfide, sulfuric acid. Formation in nature, effect on organisms, application.
25. Laboratory work.	Qualitative reactions to hydrochloric, sulfuric, hydrosulfide acids.
26. Acetic acid.	Acetic acid as one of the drugs in ancient times. Obtaining acetic acid at the present time. Application. Preparation of table vinegar from vinegar essence.
27. Salts and their biological role. Sodium chloride. Sodium carbonate.	Table salt in the history of the development of civilizations. Being in nature, prey. The biological significance of table salt. Baking soda, obtaining and application.
28. Glauber's salt. Calcium carbonate.	Finding in nature, extraction, application.
29. Practical work. Qualitative reactions to salts.
30-31. Salt hydrolysis.	Salts undergoing hydrolysis. Hydrolysis by cation, by anion. Hydrolysis equations.
32-33. Substances in the home first aid kit.	Activated carbon. coal adsorption. Iodine, history of discovery, properties, application. Hydrogen peroxide, structure, properties, application. Antimicrobial and bleaching action of hydrogen peroxide. Potassium permanganate, composition, application in medicine. Vitamins, their types, the need for vitamins. Mercury, mercury vapor toxicity. The danger of self-medication.
34. Competition of creative works. (Student presentations)

Literature

1. Akhmetov N.S. Chemistry 10-11-M.: Education 1998.
2. Goldfeld M.G. Chemistry and Society-M.: Mir 1995.
3. Grosse E. Chemistry for the curious-L .: Chemistry 1987.
4. Knunyants I.L. Chemical Encyclopedic Dictionary-M.: Soviet Encyclopedia 1983.
5. Kritsman V.A. Book for reading on inorganic chemistry (in two parts) - M .: Education 1993.
6. Trifonov D.N. How the chemical elements were discovered-M.: Prosveshchenie 1980.
7. Educational electronic edition. Chemistry for schoolchildren. Basic course 8-9 grade-MarSTU 2002
8. Kharlampovich G.D., Semenov A.S., Popov V.A. Many-sided chemistry-M.: Enlightenment 1992.
9. Chemistry: Teaching Methods No. 2.4-M.: School Press 2005.
10. Khodakov Yu.V. Inorganic chemistry. Methodical library of the school.-M .: Education 1982.
11. Electronic edition: 1C: Tutor. Chemistry-M.: Firm "1C" 1997.

Appendix. Lesson 22

Determination of the pH of some household solutions.

Objective: To consolidate the concept of the pH value of solutions. Set the pH of the proposed solutions.

Reagents given: distilled water, lemon juice, baking soda solution, Dove soap solution, laundry soap solution, CMC solution, Pantene shampoo solution, lime water, universal indicator paper. Indicators: litmus, methyl orange, phenolphthalein.

Working process :

Experience 1. Changing the color of acid-base indicators depending on the pH of solutions.

Place a few drops of each solution into a microreaction dish. Add one drop of litmus, methyl orange, and phenolphthalein to each solution.

Arrange the results of observations about the nature of the environment in the form of a table:

To determine the pH, use the following data:

Experience 2. Determination of the pH of the solution using universal indicator paper.

For an approximate determination of the pH of a solution, use universal indicator paper impregnated with a mixture of several indicators with different transition areas. The color scale attached to it indicates at what pH values ​​the indicator paper turns one color or another.

With a glass rod, transfer 2-3 drops of the test solution to universal indicator paper. Compare the color of the still wet spot with the color scale. Draw a conclusion about the approximate pH value of the solution.