Presentation of recycling waste from the production of phosphate fertilizers. Presentation "Phosphorus" presentation for a chemistry lesson (9th grade) on the topic. Nitrogen, phosphorus, and potassium are better absorbed thanks to boron

Lesson objectives:

ensure the assimilation of knowledge about phosphorus as a chemical element and a simple substance;
allotropic modifications of phosphorus;
repeat the dependence of the properties of a substance on its composition and structure;
develop the ability to compare;
contribute to the formation of a materialistic worldview and moral education of schoolchildren.

Discovery of phosphorus

Hamburg Alchemist

Henning Brand

1669

"Phosphorus" -

from Greek "luminous"

period

group

valence electrons

oxidation states

higher oxide

hydrogen connection

ALLOTROPIC MODIFICATIONS

RED

WHITE

BLACK

CHEMICAL PROPERTIES

With metals:

Ca+P=

With non-metals:

P+O 2 =

with porcelain salt explodes and ignites on impact :

KClO 3 + P = P 2 O 5 + KCl

BEING IN NATURE

ORGANISMS

MINERALS

PHOSPHOLIPIDS,

ENZYMES,

CALCIUM PHOSPHATE ETHERS

ORTHOPHOSPHORUS

ACIDS

PHOSPHORITE

TURQUOISE

APATITE

IN TEETH AND BONES

APATITE

Physiological action white phosphorus

Result applications excessive amount phosphorus

The appearance of frogs with deformities - the result applications phosphorus fertilizers that are washed into rivers and ponds,

Phosphoric necrosis– damage to the jaws

Obtaining phosphorus

heating a mixture of phosphorite, coal and

sand in an electric furnace:

Ca 3 (P.O. 4 ) 2 +C+SiO 2 → P 4 +CaSiO 3 + CO

APPLICATION OF PHOSPHORUS

fertilizers

detergents

water softening

pesticide

Defence from

corrosion

Production

matches

Production

paints

Creation

smoke screens

semiconductors

HOMEWORK

§19.9 (L.S. Guzey), §21(G.E.Rudzitis)

Individual tasks.

Prepare messages:

1) about the history of matches;

2) about the biological role of phosphorus and its compounds.

SHALL WE REPEAT?

US troops

used phosphorus

Bombs

in Iraq,

2004

WHITE PHOSPHORUS

P4 molecules have the shape of a tetrahedron. It is a low-melting substance t(melting)=44.1 o C, t(boiling)=275 o C, a soft, colorless waxy substance. It dissolves well in carbon disulfide and a number of other organic solvents. Poisonous, flammable in air, glows in the dark. Store it under a layer of water.

RED PHOSPHORUS

There are several forms of red phosphorus. Their structures have not been fully established. It is known that they are atomic substances with a polymer crystal lattice. Their melting point is 585-600 o C, color from dark brown to red and purple. Not poisonous.

BLACK PHOSPHORUS

Black phosphorus has a layered atomic crystal lattice. It is similar in appearance to graphite, but is a semiconductor. Not poisonous.

Phosphorus as a chemical element

period

group

valence electrons

oxidation states

-3, +3, +5

higher oxide

R 2 ABOUT 5

hydrogen connection

RN 3

LET'S REPEAT

1. COMPLETE THE EQUATIONS : P + F 2 = Al+P= Specify the oxidizing agent and reducing agent

2. Task:

What is the mass of phosphorus in your body if it is known that phosphorus makes up ≈1% of your body mass?

3 .Carry out transformations:

R RN 3 R 2 ABOUT 5 N 3 RO 4

Table 1. Ten countries in the world with the largest population, mid-2009, 2025 and 2050 (million people), 200920252050 1. China China India India India China USA3073. USA3583. USA Indonesia2434. Indonesia2924. Indonesia Brazil1925. Pakistan2465. Pakistan Pakistan1816. Brazil2126. Nigeria Bangladesh1627. Nigeria2077. Bangladesh Nigeria1538. Bangladesh1958. Brazil Russia1409. Russia Congo, Dem. Republic of Japan Mexico Philippines 150 9.2 billion Forecast for 2050 6 billion

Now the planet's population is more than 6 billion people and it is growing. What should I feed him??? Chemists around the world create various fertilizers to increase the amount of food grown on the earth. In 2000, every third person in the world ate grain and other agricultural products obtained through the use of mineral fertilizers. The world's population is growing, but grain production is not

To grow a full-fledged crop, cultivated plants must be protected from weeds and diseases. Chemicals used to kill weeds are called herbicides. This word comes from the Latin "coat of arms" - herb, plant and "cide" - to kill. Currently, there is a large range of complex organic compounds with herbicidal properties.

Structure of the chemical industry Basic chemistry Production of polymeric materials Production of mineral fertilizers Processing of polymeric materials Chemistry of organic synthesis Other industries (photochemistry, paint and varnish) Mining and chemical industry Industries that provide raw materials for the chemical industry (coke chemistry, oil refining, etc.)

Mineral fertilizers Depending on what nutritional elements are contained in mineral salts, fertilizers are divided into simple and complex. Simple fertilizers contain one nutrient element. These include phosphorus, nitrogen, potassium and microfertilizers. Complex fertilizers contain two or more essential nutrients simultaneously. Fertilizers can be solid (granulated, powdered) and liquid (poor up to 40% of the nutrient element and concentrated more than 40%). Mineral fertilizers are inorganic compounds containing nutrients necessary for plants.

Production of mineral fertilizers NITROGEN POTASSIUM PHOSPHATE Near raw material bases Near metallurgical plants and gas pipelines Near raw material bases Apatity Apatity Voskresensk Voskresensk Nizhny Novgorod Nizhny Novgorod Solikamsk Solikamsk Bereznyaki Bereznyaki Lipetsk Cherepovets Novgorod Novokuznetsk

Potassium fertilizers - increase the yield, quality and stability of plants. They contain the nutrient potassium, which has a positive effect on plant resistance to drought, low temperatures, pests, allows plants to use water more economically, enhances the transport of substances in the plant and the development of the root system, and promotes the accumulation of carbohydrates (sugar-beets, starch-potatoes). When it is added, photosynthesis is enhanced, the fruits acquire a brighter color and aroma, and are stored longer. The addition of potassium is necessary especially for root crops.

It was salt - “Permian”, along with valuable furs that constituted the main source of income for “Mr. Veliky Novgorod”. Salt formed the basis of the wealth of the Stroganovs, Golitsyns, and Shakhovskys. Their breweries produced up to seven million pounds of salt per year. Perm salt – “Permyanka” – was traded not only in Russia, but also in other European countries.

Phosphorus fertilizers contain the element phosphorus: 1. water-soluble (ammophos, diammophos, superphosphates), 2. sparingly soluble - very poorly soluble in weak acids, insoluble in water (phosphorite meal, bone meal). 2. sparingly soluble - very poorly soluble in weak acids, insoluble in water (phosphate rock, bone meal).

The importance of phosphorus fertilizers The meaning of phosphorus fertilizers It is part of complex proteins involved in the process of division of the cell nucleus and in the formation of new plant organs. It is part of complex proteins involved in the process of division of the cell nucleus and in the formation of new plant organs. It plays a big role in accelerating the ripening of fruits and berries. It plays a big role in accelerating the ripening of fruits and berries. Promotes economical consumption of moisture Promotes economical consumption of moisture significantly increases the winter hardiness of plants significantly increases the winter hardiness of plants Phosphorus improves the taste and enhances the flow of nutrients from the leaves to the fruits and berries. Phosphorus improves taste and enhances the flow of nutrients from leaves to fruits and berries. Phosphorus plays an important role in the life of fruit and berry crops. Phosphorus plays an important role in the life of fruit and berry crops. If there is not enough phosphorus, growth slows down, flowering and ripening are delayed, taste deteriorates, and yield decreases. If there is not enough phosphorus, growth slows down, flowering and ripening are delayed, taste deteriorates, productivity decreases.. Excess phosphorus is harmful.. Excess phosphorus is harmful.

Nitrogen is the main nutrient element for all plants: without nitrogen, the formation of proteins and many vitamins, especially B vitamins, is impossible. Nitrogen regulates the growth of vegetative mass, determines the level of crop yield, and increases the protein content in grain. Plants absorb and assimilate nitrogen most intensively during the period of maximum formation and growth of stems and leaves. Nitrogen fertilizers promote the development of the green part of the plant.

Calculation of nutritional value CO(NH 2) 2 W= n X Ar (N) X 100%/Mr substance %2 +++ W= 14 () =

Calculation of nutritional value CO(NH 2) 2 W= n X Ar (N) X 100%/Mr substance %2 +++ W = 14 () = 47%

In ancient times, salt was a valuable commodity, much of which was imported into the country from abroad. The first structures in the salt fields were: chests for storing brine, brewhouses, barns, brine-lifting pipes.. By the end of the 17th century, the extraction of salt from Solikamsk came to the fore.

TEACHING: 1. Form a concept about mineral fertilizers, their importance in the national economy and the principles of locating enterprises producing fertilizers. 2. Give a classification of fertilizers 3. Strengthen students’ skills - write chemical formulas and perform chemical calculations. 4. Teach how to compare maps of resources and production. EDUCATIONAL 1. To instill in students accuracy in note-taking. 2. Develop attentiveness when working with the map 3. Cultivate a caring attitude towards nature 4. Teach students to love their body and not eat “junk foods”

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Contents Introduction………………………………………………………………………………………. History of the development of phosphorus………………………………………………………... Natural compounds and production of phosphorus…………………………………… Chemical properties ……………………………………………………………… Allotropic changes……………………………………………………….. a) white……………………………………………………………………………….. b) red…………………………………… …………………………… c) black……………………………………………………………………. Phosphorus oxides……………………………………………………………… Orthophosphoric acid……………………………………………………… ……... Orthophosphates………………………………………………………………………. Phosphorus in the human body…………………………………………………….. Matches……………………………………………………………………………… …………………. Phosphorus fertilizers…………………………………………………………….. Conclusion……………………………………………………………… ………………. 1. Importance of phosphorus…………………………………………………………….. 2. Application of phosphorus…………………………………………………………… ………………… Bibliography………………………………………………..

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Introduction: The fifth group of the Periodic Table includes two typical elements - nitrogen and phosphorus - and subgroups of arsenic and vanadium. There is a significant difference in properties between the first and second typical elements. In the state of simple substances, nitrogen is a gas, and phosphorus is a solid. These two substances received a wide range of applications, although when nitrogen was first isolated from the air it was considered a harmful gas, and a large amount of money could be earned from the sale of phosphorus (phosphorus was valued for its ability to glow in the dark).

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History of the Discovery of Phosphorus Ironically, phosphorus was discovered several times. And every time we got it from... urine. There are references to the fact that the Arab alchemist Alhild Behil (12th century) discovered phosphorus by distilling urine mixed with clay, lime and coal. However, the date of discovery of phosphorus is considered to be 1669. The Hamburg amateur alchemist Henning Brand, a bankrupt merchant who dreamed of improving his affairs with the help of alchemy, processed a wide variety of products. Theorizing that physiological products might contain the "primordial matter" believed to be the basis of the philosopher's stone, Brand became interested in human urine. He collected about a ton of urine from soldiers' barracks and evaporated it to form a syrupy liquid. He distilled this liquid again and obtained a heavy red "urine oil", which was distilled to form a solid residue. While heating the latter, without air access, he noticed the formation of white smoke, settling on the walls of the vessel and shining brightly in the dark. Brand named the substance he obtained phosphorus, which translated from Greek means “light-bringer.” For several years, the “recipe for preparing” phosphorus was kept in the strictest confidence and was known only to a few alchemists. Phosphorus was discovered for the third time by R. Boyle in 1680. In a slightly modified form, the ancient method of producing phosphorus was also used in the 18th century: a mixture of urine with lead oxide (PbO), table salt (NaCl), potash (K2CO3) and coal (C) was heated. It was only in 1777 that K.V. Scheele developed a method for obtaining phosphorus from the horns and bones of animals.

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Natural compounds and phosphorus production Phosphorus is more abundant in the earth's crust than nitrogen, sulfur and chlorine. Unlike nitrogen, phosphorus, due to its high chemical activity, occurs in nature only in the form of compounds. The most important phosphorus minerals are apatite Ca5(PO4)3X (X - fluorine, less often chlorine and hydroxyl group) and phosphorite, the basis of which is Ca3(PO4)2. The largest apatite deposit is located on the Kola Peninsula, in the Khibiny Mountains region. Phosphorite deposits are located in the Karatau Mountains, in the Moscow, Kaluga, Bryansk regions and other places. Phosphorus is part of some protein substances contained in the generative organs of plants, in the nervous and bone tissues of animals and humans. Brain cells are especially rich in phosphorus. Nowadays, phosphorus is produced in electric furnaces by reducing apatite with coal in the presence of silica: Ca3(PO4)2+3SiO2+5C 3CaSiO3+5CO+2P Phosphorus vapor at this temperature consists almost entirely of P2 molecules, which condense into P4 molecules when cooled.

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Chemical properties Electronic configuration of the phosphorus atom 1s22s22p63s23p3 The outer electronic layer contains 5 electrons. The presence of three unpaired electrons at the outer energy level explains that in the normal, unexcited state, the valence of phosphorus is 3. But at the third energy level there are vacant cells of d-orbitals, therefore, when transitioning to the excited state, 3S electrons will separate and move to the d sublevel , which leads to the formation of 5 unpaired elements. Thus, the valency of phosphorus in the excited state is 5. In compounds, phosphorus usually exhibits an oxidation state of +5 (P2O5, H3PO4), less often +3 (P2O3, PF3), -3 (AlP, PH3, Na3P, Mg3P2).

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Allotropic modification Density m.p. Boiling point Appearance and characteristic features White 1.82 g/cm3 44.1°C 287.3°C White crystalline powder, toxic, spontaneously ignites in air. At 250-260°C it turns red (Fig. 3). Very soluble in carbon disulfide. Red 2.34 g/cm3 590°С 416°С Red crystalline or amorphous powder, non-toxic. At 220°C and 108 Pa it turns into black phosphorus. It ignites in air only when ignited. The color of red phosphorus, depending on the method and conditions of production, can vary from light red to purple and dark brown. Black 2.7 g/cm3 The most stable modification. In appearance it is similar to graphite. When heated, it turns into red phosphorus. Under normal conditions, a semiconductor conducts electric current under pressure like metal. Unlike white phosphorus, red and black phosphorus do not dissolve in carbon disulfide; they are not poisonous or flammable.

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White phosphorus The white modification of phosphorus, resulting from vapor condensation, has a molecular crystal lattice in the nodes of which P4 molecules are located. Due to the weakness of intermolecular forces, white phosphorus is volatile, fusible, can be cut with a knife and dissolves in non-polar solvents, such as carbon disulfide. White phosphorus is a very reactive substance. It reacts vigorously with oxygen, halogens, sulfur and metals. The oxidation of phosphorus in air is accompanied by heating and glowing. Therefore, white phosphorus is stored under water, with which it does not react. White phosphorus is very toxic. About 80% of the total production of white phosphorus goes to the synthesis of pure orthophosphoric acid. It, in turn, is used to produce sodium polyphosphates (they are used to reduce the hardness of drinking water) and food phosphates. The remainder of the white phosphorus is used to create smoke-forming substances and incendiary mixtures. Safety precautions. In the production of phosphorus and its compounds, special precautions are required, because white phosphorus is a strong poison. Prolonged work in an atmosphere of white phosphorus can lead to bone disease, tooth loss, and necrosis of jaw areas. When ignited, white phosphorus causes painful burns that do not heal for a long time. White phosphorus should be stored under water in sealed containers. Burning phosphorus is extinguished with carbon dioxide, CuSO4 solution or sand. Burnt skin should be washed with a solution of KMnO4 or CuSO4. The antidote for phosphorus poisoning is a 2% solution of CuSO4. During long-term storage, as well as when heated, white phosphorus turns into a red modification (it was first obtained only in 1847). The name red phosphorus refers to several modifications that differ in density and color: it ranges from orange to dark red and even purple. All varieties of red phosphorus are insoluble in organic solvents, and compared to white phosphorus, they are less reactive and have a polymeric structure: these are P4 tetrahedra linked to each other in endless chains.

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Red and black phosphorus Red phosphorus is used in metallurgy, the production of semiconductor materials and incandescent lamps, and is used in match production. The most stable modification of phosphorus is black phosphorus. It is obtained by the allotropic transformation of white phosphorus at t=2200C and elevated pressure. In appearance it resembles graphite. The crystal structure of black phosphorus is layered, consisting of corrugated layers (Fig. 2). Black phosphorus is the least active modification of phosphorus. When heated without access to air, it, like red, turns into steam, from which it condenses into white phosphorus.

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An experiment illustrating the transition of red phosphorus to white 1-molecules of white phosphorus; 2-crystal. black phosphorus grid 3

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Phosphorus (V) oxide - P2O5 Phosphorus forms several oxides. The most important of them is phosphorus (V) oxide P4O10. Often its formula is written in a simplified form - P2O5. The structure of this oxide retains the tetrahedral arrangement of phosphorus atoms. White crystals, t pl.= 5700°C, t boil.= 6000°C, ρ= 2.7 g/cm3. Has several modifications. In vapor it consists of P4H10 molecules, it is very hygroscopic (used as a desiccant for gases and liquids). Preparation: 4P + 5O2 = 2P2O5 Chemical properties All chemical properties of acidic oxides: reacts with water, basic oxides and alkalis 1) P2O5 + H2O = 2HPO3 (metaphosphoric acid) P2O5 + 2H2O = H4P2O7 (pyrophosphoric acid) P2O5 + 3H2O = 2H3PO4 (orthophosphoric acid) acid) 2) P2O5 + 3BaO =Ba3(PO4)2 Due to its exceptional hygroscopicity, phosphorus oxide (V) is used in laboratory and industrial technology as a drying and dehydrating agent. In its drying effect it surpasses all other substances.

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Orthophosphoric acid. Several acids containing phosphorus are known. The most important of them is orthophosphoric acid H3PO4. Anhydrous orthophosphoric acid is light transparent crystals that diffuse in air at room temperature. Melting point 42.35°C. Phosphoric acid forms solutions of any concentration with water.

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Orthophosphoric acid. Preparation of orthophosphoric acid In the laboratory In industry, oxidation of phosphorus with 30% nitric acid: 3P + 5NO3 + 2H2O = 3H3PO4 + 5NO Extraction method Thermal method treatment of crushed natural phosphates with sulfuric acid: 2P + 5H2SO4 = 2H3PO4 + 5SO2 + 2H2O Orthophosphoric acid is then filtered and concentrated by evaporation. The thermal method consists of reducing natural phosphates to free phosphorus, followed by burning it to P4O10 and dissolving the latter in water. Phosphoric acid produced using this method is characterized by higher purity and increased concentration (up to 80%).

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Physical properties of H3PO4 Orthophosphoric acid in its pure form under ordinary conditions is colorless orthorhombic crystals, melting at a temperature of 42.3 ° C. However, chemists rarely encounter such an acid. Much more often they deal with the hemihydrate H3PO4 * 0.5 H2O, which precipitates in the form of colorless hexagonal prisms when concentrated aqueous solutions of orthophosphoric acid are cooled. The melting point of the hemihydrate is 29.3°C. Pure H3PO4 after melting forms a viscous oily liquid with low electrical conductivity and greatly reduced diffusion ability. These properties, as well as a detailed study of the spectra, show that the H3PO4 molecules in this case are practically not dissociated and are united by strong hydrogen bonds into a single macromolecular structure. As a rule, molecules are connected to each other by one, less often by two, and very rarely by three hydrogen bonds. If an acid is diluted with water, its molecules are more likely to form hydrogen bonds with water than with each other. Because of such “sympathies” for water, the acid mixes with it in any relationship. The hydration energy here is not as high as that of sulfuric acid, so the heating of H3PO4 upon dilution is not so strong and dissociation is less pronounced. According to the first stage of dissociation, orthophosphoric acid is considered an electrolyte of medium strength (25 - 30%), according to the second - weak, and according to the third - very weak.

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The chemical properties of orthophosphoric acid are common to other acids and specific: 1. An aqueous solution of the acid changes the color of the indicators. Dissociation occurs in stages: H3PO4--->H++H2PO4-H2PO-4--->H++HPO42-HPO42- --->H++PO43- Dissociation is easiest in the first step and most difficult in the third 2. Reacts with metals located in the displacement series before hydrogen: 6Na+2H3PO4 --->2Na3PO4+3H2 3. Reacts with basic oxides: 3CaO+2H3PO4 --->Ca3(PO4)2+3H2O 4. Reacts with bases and ammonia; if the acid is taken in excess, then acid salts are formed: H3PO4 + 3NaOH ---> Na3PO4 + 3H2O H3PO4 + 2NH3 ---> (NH4)2HPO4 H3PO4 + NaOH ---> NaH2PO4 + H2O 5. Reacts with salts of weak acids: 2H3PO4 + 3Na2CO3 -->2Na3PO4 + 3CO2 + 3H2O 1. When heated, it gradually turns into metaphosphoric acid: 2H3PO4 ---> H4P207 + H20 (diphosphoric acid) H4P2O7 ---> 2HPO3 + H2O 2. Under the action of a solution of silver nitrate (I ) a yellow precipitate appears: H3PO4+ZAgNO3---> Ag3P04+3HN03 yellow precipitate 3. Orthophosphoric acid plays an important role in the life of animals and plants. Its residues are part of adenosine triphosphoric acid ATP. The decomposition of ATP releases a large amount of energy. You will learn more about ATP in the course of general biology and organic chemistry.

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Chemical properties of H3PO4 When neutralizing phosphoric acid with alkalis, salts are formed: dihydrogen phosphates, hydrogen phosphates, as well as phosphates, for example: H3PO4 + NaOH = NaH2PO4 + H2O sodium dihydrogen phosphate H3PO4 + 2NaOH = Na2HPO4 + 2H2O sodium hydrogen phosphate H3PO4 + 3NaOH = Na3PO4 + 3H2O sodium phosphate

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Phosphorus in the human body In the human body weighing 70 kg. Contains about 780 g of phosphorus. Phosphorus is present in the form of calcium phosphates in human and animal bones. It is also part of proteins, phospholipids, and nucleic acids; Phosphorus compounds are involved in energy metabolism (adenesine triphosphoric acid, ATP). The daily requirement of the human body for phosphorus is 1.2 g. We consume the main amount of it with milk and bread (100 g of bread contains approximately 200 mg of phosphorus). Fish, beans and some types of cheese are richest in phosphorus. Interestingly, for proper nutrition it is necessary to maintain a balance between the amount of phosphorus and calcium consumed: the optimal ratio in these food elements is 1.5/1. Excess phosphorus-rich foods lead to leaching of calcium from bones, and with excess calcium, urolithiasis develops.

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Matches The burning surface of a matchbox is coated with a mixture of red phosphorus and glass powder. The composition of the match head includes oxidizing agents (PbO2, KСlO3, BaCrO4) and reducing agents (S, Sb2S3). When friction from the ignition surface occurs, the mixture applied to the match ignites. The first phosphorus matches - with a head made of white phosphorus - were created only in 1827. 6P + 5KCLO3 = 5KCL + 3P2O5 Such matches ignited when rubbed against any surface, which often led to fires. In addition, white phosphorus is very poisonous. Cases of poisoning with phosphorus matches have been described, both due to careless handling and for the purpose of suicide: for this it was enough to eat a few match heads. That is why phosphorus matches were replaced by safe ones, which serve us faithfully to this day. Industrial production of safety matches began in Sweden in the 60s. XIX century.

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Mineral fertilizers Name of fertilizer Chemical composition Color and appearance Obtained in industry and found in nature 1. Nitrogen fertilizers Sodium nitrate (sodium nitrate) NaNO3 (15-16% N) White or gray crystalline substance with hygroscopic properties (gray color is given by impurities) Obtained in the production of nitric acid. Nitrous gases (N0 and NO2), not absorbed by water, are passed through soda solutions: Na2CO3+2NO2 --> NaNO3+NaNO2+CO2 Potassium nitrate (potassium nitrate) KN03 (12.5-13% N) White crystalline substance Relatively small deposits of KNO3 are located in Central Asia. In industry it is obtained as follows: KCl + NaNO3 --->NaCl + KN03 Ammonium nitrate (ammonium nitrate) NH4NO3 (15-16% N) White crystalline, very hygroscopic substance Obtained by neutralizing 48 - 60% nitric acid with ammonia: NH3 +HNO3 --->NH4NO3 The resulting solution is concentrated and crystallization is carried out in special towers

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Mineral fertilizers Name of fertilizer Chemical composition Color and appearance Obtained in industry and found in nature 1. Nitrogen fertilizers Ammonium sulfate (NH4)2S04 (20.5-21% N) White (gray or greenish due to impurities) crystalline powder , slightly hygroscopic Obtained by the reaction of ammonia with sulfuric acid: 2NH3+H2SO4 --->(NH4)2SO4 Urea CO(NH2)2 (46% N) White fine-crystalline, hygroscopic, sometimes granular substance Obtained by the interaction of ox- carbon dioxide (IV) with ammonia (at high pressure and temperature): CO2+2NH3 --->CO(NH2)2+H2O 2.. Phosphorus fertilizers Simple superphosphate Ca(H2P04)2 2H2O CaSO4∙2H2O (up to 20% P2O5 ) Gray fine-grained powder Obtained by the interaction of phosphorites or apatites with sulfuric acid: Ca3(PO4)2+2H25O4 ---> Ca(H2PO4)2+2CaSO4

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Mineral fertilizers Name of fertilizer Chemical composition Color and appearance Obtained in industry and found in nature 2.. Phosphorus fertilizers Double superphosphate Ca (H2PO4)2 H2O (40% P205) Similar to simple superphosphate Production is carried out in two stages: a) Ca3 (PO4 )2 + 3H2SO4 --> 2H3PO4 + 3CaSO4 CaSO4 settles and is separated by filtration: b) Ca3(P04)2 + 4H3P04 --> 3Ca(H2P04)2 3. Potassium fertilizers Potassium chloride KCl (52-60% K20) White fine crystalline substance Potassium chloride occurs in nature in the form of the mineral sylvinite (NaCI∙KCI)

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Mineral fertilizers Name of fertilizer Chemical composition Color and appearance Obtained in industry and found in nature 3. Potassium fertilizers Dihydroortho ammonium phosphate NH4H2PO4 (with impurities) White (grayish due to impurities) crystalline powder Obtained by reacting orthophosphoric acid with ammonia: NH3+H3P04 ---> NH4H2PO4 Ammonium hydrogen orthophosphate (NH4)2HPO4 with (NH4)2S04 and other impurities Same as ammonium dihydrogen orthophosphate Prepared similarly to ammonium dihydrogen orthophosphate: 2NH3+H3P04 ---> (NH4)2HPO4

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The importance of phosphorus Phosphoric acid is of great importance as one of the most important components of plant nutrition. Phosphorus is used by plants to build their most vital parts - seeds and fruits. Derivatives of orthophosphoric acid are very necessary not only for plants, but also for animals. Bones, teeth, shells, claws, needles, and spines in most living organisms consist mainly of calcium orthophosphate. In addition, orthophosphoric acid, forming various compounds with organic substances, actively participate in the metabolic processes of a living organism with the environment. As a result, phosphorus derivatives are found in bones, brain, blood, muscle and connective tissues of humans and animals. There is especially a lot of orthophosphoric acid in the composition of nerve (brain) cells, which allowed A.E. Fersman, a famous geochemist, called phosphorus “the element of thought.” A decrease in the content of phosphorus compounds in the diet or their introduction in an indigestible form has a very negative effect on the state of the body (animal disease with rickets, anemia, etc.).

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Application of phosphorus Orthophosphoric acid is currently used quite widely. Its main consumer is the production of phosphate and combined fertilizers. For these purposes, about 100 million tons of phosphorus-containing ore are mined annually throughout the world. Phosphorus fertilizers not only help increase the productivity of various agricultural crops, but also give plants winter hardiness and resistance to other unfavorable climatic conditions, and create conditions for faster ripening of crops in areas with short growing season. They also have a beneficial effect on the soil, promoting its structuring, the development of soil bacteria, changing the solubility of other substances contained in the soil and suppressing some of the harmful organic substances that are formed. The food industry consumes a lot of orthophosphoric acid. The fact is that diluted orthophosphoric acid tastes very pleasant and its small additions to marmalades, lemonades and syrups significantly improve their taste. Some salts of phosphoric acid also have this property. Calcium hydrogen phosphates, for example, have long been included in baking powders, improving the taste of buns and bread. Other industrial applications of orthophosphoric acid are also interesting. For example, it was noticed that impregnation of wood with the acid itself and its salts makes the wood non-flammable. On this basis, fire-retardant paints, non-flammable phosphorus wood boards, non-flammable phosphate foam and other building materials are now produced. Various salts of phosphoric acid are widely used in many industries, in construction, various fields of technology, in public utilities and everyday life, for protection against radiation, for softening water, combating boiler scale and making various detergents. Phosphoric acid, condensed acids and dehydrated phosphates serve as catalysts in the processes of dehydration, alkylation and polymerization of hydrocarbons. Organophosphorus compounds occupy a special place as extractants, plasticizers, lubricants, powder additives and absorbents in refrigeration units. Salts of acid alkyl phosphates are used as surfactants, antifreeze, special fertilizers, latex anticoagulants, etc. Acid alkyl phosphates are used for extraction processing of uranium ore liquors.

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Tasks Phosphorus 1. Write the electronic formula of the phosphorus atom. Explain what happens to the electronic configuration of an atom when it exhibits the highest oxidation state. 2. What oxidation states can phosphorus exhibit in compounds? Give examples of these compounds. Write the electronic formula of the phosphorus atom in the oxidation state +3. 3. What are the main differences in the physical and chemical properties of red and white phosphorus. How can you separate red phosphorus from the white admixture? 4. Calculate the relative density of phosphine in hydrogen and air. Is phosphine lighter or heavier than these gases? 5. How can a transition be made from red phosphorus to white and back? Are these processes chemical phenomena? Explain your answer. 6. Calculate the mass of phosphorus that must be burned in oxygen to obtain phosphorus oxide (V) weighing 3.55 g? 7. A mixture of red and white phosphorus weighing 20 g was treated with carbon disulfide. The undissolved residue was separated and weighed; its mass was 12.6 g. Calculate the mass fraction of white phosphorus in the initial mixture. 8. What is the type of chemical bond in the compounds: a) PH3; b) PCl5; c) Li3P. In polar substances, indicate the direction of displacement of common electron pairs. 9. Phosphine can be prepared by the action of hydrochloric acid on calcium phosphide. Calculate the volume of phosphine (normal conditions) that is formed from 9.1 g of calcium phosphide. The mass fraction of the product yield is 90%.

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Orthophosphoric acid and its salts 1. Write the reaction equations between orthophosphoric acid and the following substances: a) magnesium oxide; b) potassium carbonate; c) silver nitrate; d) iron (II) sulfate. 2. Write down equations for the reactions between orthophosphoric acid and potassium hydroxide, as a result of which 3 types of salts are formed: medium and two acidic. 3. Which acid is a stronger oxidizing agent: nitric or phosphoric? Explain your answer. 4. Write the reaction equations with which you can carry out the following transformations: P → Р205 →Н3Р04 → Na3Р04 → Ca3(Р04)2 5. With the help of which reactions you can carry out the following transformations: Р →Са3Р2 →РН3 →Р2О5 →К3Р04 →Са3 (P04)2→Ca(H2P04)2 Write the equations for these reactions. 6. Using the electronic balance method, select the coefficients in the schemes of the following redox reactions: a) РН3 + O2 →Р2О5 + Н2О b) Ca3(РО4)2 + C + SiO2 →CaSiO3 + P + CO 7. What is the mass of the solution with mass with a proportion of phosphoric acid of 40% can be obtained from phosphorite weighing 100 kg with a mass fraction of Ca3(PO4)2 of 93%? 8. Phosphoric acid weighing 195 kg was obtained from natural phosphorite weighing 310 kg. Calculate the mass fraction of Ca3(PO4)2 in natural phosphorite. 9. An aqueous solution containing phosphoric acid weighing 19.6 g was neutralized with calcium hydroxide weighing 18.5 g. Determine the mass of the resulting precipitate CaHPO4 2H2O. 10. There is a solution of phosphoric acid weighing 150 g (mass fraction of H3PO4 24.5%). Calculate the volume of ammonia (normal conditions) that must be passed through the solution to obtain ammonium dihydrogen phosphate. 11. What salt is formed if potassium hydroxide weighing 2.8 g is added to a solution containing H3PO4 weighing 4.9 g? Calculate the mass of salt obtained

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Mineral fertilizers 1. What nitrogen and phosphorus fertilizers do you know? Write down the reaction equations for their preparation. Why do plants need nitrogen and phosphorus? 2. Determine the mass fraction of phosphorus oxide (V) in the CaHPO4 2H2O precipitate. 3. The mass fraction of phosphorus (V) oxide in superphosphate is 20%. Determine the mass of superphosphate that must be introduced under the fruit tree if phosphorus weighing 15.5 g is required for the normal development of the tree. 4. The mass fraction of nitrogen in the fertilizer is 14%. All nitrogen is included in the fertilizer as urea CO (NH2)2. Calculate the mass fraction of urea in this fertilizer. 5. In superphosphate, the mass fraction of phosphorus oxide (V) is 25%. Calculate the mass fraction of Ca(H2PO4)2 in this fertilizer. 6. Calculate the mass of ammonium sulfate that should be taken to add nitrogen weighing 2 tons to the soil over an area of 5 hectares. What mass of fertilizer should be applied to each square meter of soil? 7. Calculate the mass of ammonium nitrate that should be applied to an area of 100 hectares, if the mass of nitrogen applied to an area of 1 hectare should be 60 kg. 8. Phosphorus (V) oxide weighing 0.4 kg must be introduced into the soil under the fruit tree. What mass of superphosphate should be taken in this case, if the mass fraction of assimilable phosphorus oxide (V) in it is 20%? 9. Under the fruit tree it is necessary to apply ammonium nitrate weighing 140 g (the mass fraction of nitrogen in nitrate is 35%). Determine the mass of ammonium sulfate, which can be used to add the same amount of nitrogen.

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List of used literature: 1. F.G.Feldman, G.E.Rudzitis. CHEMISTRY. Textbook for 9th grade of general education institutions. – M., 5th edition, ENLIGHTENMENT, 1997. 2. CHEMISTRY. Reference materials. Edited by Yu.D. Tretyakov, - M., EDUCATION, 1984. 3. CHEMISTRY. Schoolchildren's Handbook, - M., 1995. 4. CHEMISTRY. Encyclopedia for children. Volume 17, AVANTA, 2000 5. Weser W.-J., Phosphorus and its compounds, trans. from English, - M., 1963. 6. Internet: http://school-sector.relarn.ru/nsm/chemistry/

Story

Phosphorus was discovered by the Hamburg alchemist Hennig Brand in 1669

Hennig Brand

Somewhat later, phosphorus was obtained by another German chemist - Johann Kunkel

Johann Kunkel

Phosphorus is a simple substance (proved by Lavoisier)

Lavoisier

Element characteristics

III period

V group

main p/gr. (A)

5 valence electrons

Oxidation states:

-3, +3, +5

Physical properties

Elemental phosphorus under normal conditions represents three stable allotropic modifications:

white red black

White phosphorus P4

A soft, colorless substance, poisonous, has a garlicky odor,

t°pl.= 44°C, t°boiling= 280°C, soluble in carbon disulfide (CS 2 ), volatile It is very reactive, oxidizes in air (and spontaneously ignites), and glows in the dark.

In the famous work “The Hound of the Baskervilles” by A. Conan Doyle, phosphorus is mentioned.

“ … Yes! It was a dog, huge, pitch black. But none of us mortals have ever seen such a dog. Flames erupted from her open mouth, her eyes threw sparks, and iridescent fire flickered across her muzzle and nape. No one’s fevered brain could have produced a vision more terrible, more disgusting than this hellish creature that jumped out at us from the fog... A terrible dog, the size of a young lioness. Its huge mouth still glowed with a bluish flame, its deep-set wild eyes were surrounded by fiery circles. I touched this luminous head and, taking my hand away, saw that my fingers also glowed in the dark.

– Phosphorus, I said.”

Was he right?

Arthur

Conan Doyle?

Red phosphorus P

Odorless, red-brown color, non-toxic. The atomic crystal lattice is very complex, usually amorphous. Insoluble in water and organic solvents. Stable. Doesn't glow in the dark

Black phosphorus

A polymeric substance with a metallic luster, similar to graphite, odorless, greasy to the touch. Insoluble in water and organic solvents. Atomic crystal lattice, semiconductor. t°bp.= 453°С (sublimation),

t°melt.= 1000°C

Receipt

White phosphorus is obtained by reducing calcium phosphate (in an electric furnace):
Ca 3 (P.O. 4 ) 2 + 3SiO 2 + 5C t°

3CaSiO 3 + 5CO + 2P

Kr clear and black

phosphorus is obtained from white

Chemical properties

1. Interaction with oxygen:

4P+5O 2 (izb.) = 2P 2 ABOUT 5 ( phosphorus oxide V )

2 .Interaction with halogens:

2Р+5С l 2 (izb.) = 2PCl 5 (phosphorus chloride V )

2P+3 Cl 2(insufficient) = 2 PCl 3 (phosphorus chloride III )

3. Interaction with sulfur:

2P + 5 S (izb.) =P 2 S 5 (phosphorus sulfide V )

2P+3S ( insufficient) =P 2 S 3 (phosphorus sulfide III)

Phosphorus interaction with water

4P+6H 2 O=PH 3 + 3H 3 P.O. 2

phosphorous acid

Salts of this acid are called hypophosphites

In them, phosphorus exhibits an oxidation state +1!

Phosphorus in nature

The phosphorus content in the earth's crust is 9.3·10-2 (by mass). In nature, phosphorus occurs only in the form of compounds. The main phosphorus minerals are phosphorite Ca 3 (P.O. 4 ) 2 and apatite 3Ca 3 (P.O. 4 ) 2 CaF 2 .
In addition, phosphorus is part of protein substances, as well as bones and teeth.