Non-metals in nature. In nature, there are native non-metals N2 and O2 (in the air), sulfur (in the earth's crust), but more often non-metals in nature are in a chemically bound form. First of all, it is water and salts dissolved in it, then minerals and rocks (for example, various silicates, aluminosilicates, phosphates, borates, sulfates and carbonates). In terms of prevalence in the earth's crust, non-metals occupy a variety of places: from the three most common elements (O, Si, H) to very rare ones (As, Se, I, Te).
slide 3 from the presentation "Chemistry of non-metals". The size of the archive with the presentation is 1449 KB.Chemistry Grade 9
summary of other presentations"Chemistry of non-metals" - Chemical structure and properties of metals and non-metals. Allotropy of carbon. The position of metals in the Periodic system of chemical elements. Presentation of a lesson in chemistry for grade 9. Non-metals in nature. Nonmetals. red phosphorus. Topic: NON-METALS. Oxygen. M. Allotropy. Physical properties of non-metals. Diamond. Non-metals also include hydrogen H and inert gases. General characteristics and properties of non-metals.
"Non-metals" - ELECTRICITY SERIES OF NON-METALS. Solid carbon silicon. What explains the diversity of the aggregate state of non-metals. Lattice) Red phosphorus - white phosphorus (molecular structure of P2 and P4). Do you think there are more metals or non-metals in the table? Test. Nonmetals. Examples: Diamond - graphite (crystal. Chemistry Grade 9 Teacher Kuleshova S.E. Liquid Bromine. Allotropy. Name the most active and strong non-metals. Oxygen O2 and Ozone O3. Aggregate state. Gaseous Oxygen, hydrogen. Physical properties.
"Halogen Chemistry" - The biological role of chlorine. Research results. Enzymes become active in an acidic environment at 37-38 °C. The results of the study distribution in nature. Participates in the formation of hydrochloric acid, metabolism, tissue construction. Conclusions and recommendations. The biological role of bromine. Dissolution of sodium bromide in water Yellow precipitate AgBr?. Goals and objectives. Research results discovery of halogens. Project prospects. 2011, Petropavlovskoye village.
"Alkadienes chemistry" - Alkadienes with isolated double bonds. Central atom C-Sp3 hybridization. Chemistry lesson in grade 9 Teacher: Dvornichena L.V. Updating previously acquired knowledge. Allene structure diagram. Alkadienes: structure, nomenclature, homologues, isomerism. A game. The outermost atom is C-Sp2 hybridization. Alkadienes with cumulated arrangement of double bonds. Nomenclature of alkadienes. Conjugated Alkadienes.
"Chemical Equilibrium" - Task 2: Write the kinetic equations for chemical reactions. Irreversible. Changes in the forward and reverse reaction rates in the process of establishing chemical equilibrium. chemical balance. Vpr = Vrev. Task 1: Write the factors that affect the rate of chemical reactions. I option hcl + O2?H2O + cl2. Chemical reactions. II option H2S + SO2 ? S + H2O. Reversible.
"Characteristics of metals" - The use of metals in human life. Properties of metals. General characteristics. Good electrical conductivity. General characteristics of metals. Finding metals in nature. Variety of metals. Other metals corrode but do not rust. Metals are one of the foundations of civilization on planet Earth. Rusting and corrosion of metals. Metals. Content of the work: Of the medicines containing precious metals, the most common are lapis, protargol, etc.
In air, white phosphorus really glows in the dark. A little friction is enough to ignite the phosphorus with the release of a large amount of heat. This means that if phosphorus covered the dog's hair, then it would get burned and die before attacking a person.
For atoms of non-metal elements in a period with an increase in the serial number, the charge of the nucleus increases; the atomic radii decrease; the number of electrons on the outer layer increases; the number of valence electrons increases; electronegativity increases; oxidizing (non-metallic) properties are enhanced (except for elements of group VIIIA).
For atoms of non-metal elements in a subgroup (in a long-period table - in a group), with an increase in the serial number, the charge of the nucleus increases; the radius of the atom increases; electronegativity decreases; the number of valence electrons does not change; the number of external electrons does not change (with the exception of hydrogen and helium); oxidizing (non-metallic) properties weaken (except for elements of group VIIIA).
simple substances. Most non-metals are simple substances in which the atoms are linked by covalent bonds; There are no chemical bonds in noble gases. Non-metals include both molecular and non-molecular substances. All this leads to the fact that there are no physical properties characteristic of all non-metals.
Non-metals in nature In nature, there are native non-metals N2 and O2 (in the air), sulfur (in the earth's crust), but more often non-metals in nature are in a chemically bound form. First of all, it is water and salts dissolved in it, then minerals and rocks (for example, various silicates, aluminosilicates, phosphates, borates, sulfates and carbonates). In terms of prevalence in the earth's crust, non-metals occupy a variety of places: from the three most common elements (O, Si, H) to very rare ones (As, Se, I, Te).
Oxygen is a colorless gas, while ozone has a pale purple color. Ozone is more bactericidal (lat. itzdao "to kill") than oxygen. Therefore, ozone is used to disinfect drinking water. Ozone is able to retain the ultraviolet rays of the solar spectrum, which are detrimental to all life on Earth, and therefore the ozone screen, which is located in the atmosphere at an altitude of 2035 km, protects life on our planet Oxygen
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Presentation on chemistry by a student of grade 9b of gymnasium No. 24 named after. I.A. Krylova Sergeeva Irina on the topic “Non-metals. Arsenic"slide 2
Arsenic Characteristics of the element Arsenic (Arsenicum) is a chemical element with atomic number 33 in the periodic system of DIMendeleev, denoted by the symbol As. Serial number - 33 Nuclear charge = +33 Number of electrons = 33 Relative atomic mass = 74.92 (≈ 75) Period number - IV Number of electronic levels = 4 Group number - V, main subgroup Number of electrons at the last level = 5 Electronic passport - 1s²2s²2p63s²3p63d104s²4p³ Electronegativity - 2.18 (Pauling scale) Possible oxidation states = -3, 0, +3, +5
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Facts from history Arsenic has been known since ancient times: 1. in the writings of Dioscorides (1st century AD) the calcination of a substance, which is now called arsenic sulfide, is mentioned; 2. in the III-IV centuries. in fragmentary records attributed to Zozymos (Egyptian or Greek alchemist), there is a mention of metallic arsenic; 3. The Greek writer Olympiodorus (5th century AD) describes the manufacture of white arsenic by roasting sulfide; 4. in the VIII century. the Arab alchemist Geber obtained arsenic trioxide; 5. In the Middle Ages, people began to encounter arsenic trioxide when processing arsenic-containing ores, and the white smoke of gaseous As2O3 was called ore smoke; Dioscorides Geber
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6. The production of free metallic arsenic is attributed to the German alchemist Albert von Bolstedt and dates back to about 1250, although Greek and Arab alchemists undoubtedly obtained arsenic (by heating its trioxide with organic substances) before Bolstedt; 7. in 1733 it was proved that white arsenic is “earth”, an oxide of metallic arsenic; 8. in 1760 the Frenchman Louis Claude Cadé received the first organic compound of arsenic, known as Cadé liquid or "cacodyl" oxide; the formula of this substance is [(CH3)2As]2O; 9. in 1775, Karl Wilhelm Scheele obtained arsenic acid and arsenic hydrogen; 10. In 1789, Antoine Laurent Lavoisier recognized arsenic as an independent chemical element. Albert von Bolstedt K.W. Sheele A.L. Lavoisier
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Arsenic is a simple substance Arsenic is a silver-gray or tin-white substance, with a metallic sheen when freshly broken. But it quickly fades in air. It is a brittle steel-colored semimetal (located in the periodic table on the border between metals and nonmetals, which is why it is called "semimetal"). Arsenic, like other semimetals, is characterized by the formation of a covalent crystal lattice and the presence of metallic conductivity. However, arsenic is a non-metal. Physical properties: 1. When heated above 600°C, arsenic sublimates without melting, but under a pressure of 37 atm. Melts at 818°C. 2. Density (at n.a.) - 5.73 g / cm³ (gray arsenic) 3. Boiling point = 876 K (Kelvin) Appearance of a simple substance
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Allotropic modifications of arsenic Despite the fact that arsenic belongs to non-metals, it has 4 allotropic modifications - white, yellow, black and metallic (or gray) arsenic. The last 2 have the properties of metals. 1. Gray arsenic is a brittle gray-steel crystalline mass with a metallic luster, which quickly disappears in air due to oxidation of the surface layer. 2. Black arsenic - its most stable form - a black powder, like most metals, in a fine (very fine, which can pass through a sieve.) state (remember black silver). In contrast to the gray form, it is stable in air, but at 2859 ° C it turns into a gray form. Black arsenic Gray arsenic (metal)
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Found in nature Arsenic is a trace element. The content in the earth's crust is 1.7×10−4% by weight. In sea water 0.003 mg/l. This substance can occur in its native state, has the form of metallic lustrous gray shells or dense masses consisting of small grains. About 200 arsenic-containing minerals are known. In small concentrations, it is often found in lead, copper and silver ores. Quite often there are two natural compounds of arsenic with sulfur: orange-red transparent realgar AsS and lemon-yellow orpiment As2S3. A mineral of industrial importance - arsenopyrite (arsenic pyrites) FeAsS or FeS2 FeAs2 (46% As), arsenic pyrites - lollingite (FeAs2) (72.8% As), scorodite FeAsO4 (27 - 36% As) are also mined. Most of the arsenic is mined incidentally during the processing of arsenic-containing gold, lead-zinc, copper pyrite and other ores. Scorodite Lollingit
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Arsenopyrite Realgar Orpiment Thin (2 mm thick) crystalline crust of native arsenic at the contact of a dolomite veinlet with host gneiss (rock). Native arsenic. Vorontsovskoye gold deposit. Northern Ural. Buds of native arsenic on the wall of a carbonate veinlet in an ore skarn.
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Obtaining arsenic Arsenic is produced industrially by heating arsenic pyrite: FeAsS = FeS + As or (more rarely) by reduction of As2O3 with coal. Both processes are carried out in refractory clay retorts connected to a receiver for arsenic vapor condensation. Arsenic anhydride is produced by the oxidative roasting of arsenic ores or as a by-product of the roasting of polymetallic ores, which almost always contain arsenic. During oxidative roasting, As2O3 vapors are formed, which condense in the trapping chambers. Raw As2O3 is purified by sublimation at 500-600°C. Purified As2O3 is used for the production of arsenic and its preparations. Currently, to obtain metallic arsenic, arsenopyrite is most often heated in muffle furnaces without air access. In this case, arsenic is released, the vapors of which condense and turn into solid arsenic in iron pipes coming from furnaces and in special ceramic receivers. The residue in the furnaces is then heated with air access, and then the arsenic is converted to As2O3. Metallic arsenic is obtained in rather small quantities, and the main part of arsenic-containing ores is processed into white arsenic, that is, into arsenic trioxide - arsenic anhydride As2O3. Muffle furnace Scheme of a refractory clay retort
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Chemical properties of arsenic Arsenic combines directly with halogens; under normal conditions, AsF5 is a gas; AsF3, AsCl3, AsBr3 - colorless, volatile liquids; AsI3 and As2I4 are red crystals. When arsenic was heated with sulfur, sulfides were obtained: orange-red As4S4 and lemon-yellow As2S3. Pale yellow As2S5 sulfide precipitates when H2S is passed into an ice-cooled solution of arsenic acid (or its salts) in fuming hydrochloric acid: 2H3AsO4 + 5H2S = As2S5 + 8H2O; around 500 °C it decomposes into As2S3 and sulfur. All arsenic sulfides are insoluble in water and dilute acids. Strong oxidizers (mixtures of HNO3 + HCl, HCl + KClO3) transform them into a mixture of H3AsO4 and H2SO4. Sulfide As2S3 easily dissolves in sulfides and polysulfides of ammonium and alkali metals, forming acid salts - thioarsenic H3AsS3 and thiomarsenic H3AsS4. Sulfur (powder)
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Arsenic-Poison In the minds of many, the words "poison" and "arsenic" are identical. This has already happened historically. There are stories about the poisons of Cleopatra. The poisons of Locusta were famous in Rome. Poison was also a common tool for eliminating political and other opponents in the medieval Italian republics. In Venice, for example, experts in poisoning were kept at the court. And the main component of almost all poisons was arsenic. In Russia, the law prohibiting the sale of “vitriol and amber oil, strong vodka, arsenic and cilibukha” to private individuals was issued back in the reign of Anna Ioannovna - in January 1733. The law was extremely strict and read: “Who will continue with that arsenic and other above-mentioned materials will be traded and with that caught or who will be reported to, they will be severely punished and exiled, they will be exiled without any mercy, the same will be inflicted on those who by pharmacies and town halls will buy from whom. And if someone, having bought such poisonous materials, will repair damage to people, those who are searched for will not only be tortured, but they will also be executed by death, depending on the importance of the matter without fail. Arsenic Poison (Poison "Arsenious") Empress Anna Ioannovna
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For centuries, arsenic compounds have attracted (and continue to attract) the attention of pharmacists, toxicologists, and forensic scientists. Criminalists have learned to recognize arsenic poisoning unmistakably. If white porcelain-like grains are found in the stomach of the poisoned, then the first thing to do is to suspect arsenic anhydride As2O3. These grains, together with pieces of coal, are placed in a glass tube, sealed and heated. If there is As2O3 in the tube, then a gray-black shiny ring of metallic arsenic appears on the cold parts of the tube. After cooling, the end of the tube is broken off, the charcoal is removed, and the grey-black ring is heated. In this case, the ring is distilled to the free end of the tube, giving a white coating of arsenic anhydride. The reactions here are: As2O3 + 3C → As2 + 3CO or 2As2O3 + 3C → 2As2 + 3CO2; 2As2 + 3O2 → 2As2O3. The resulting white plaque is placed under a microscope: already at low magnification, characteristic shiny crystals in the form of octahedrons (a polyhedral crystal) are visible. View of the octahedron
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Symptoms of poisoning Symptoms of arsenic poisoning are a metallic taste in the mouth, vomiting, severe abdominal pain. Later convulsions, paralysis, death. The most well-known and widely available antidote for arsenic poisoning is milk, more precisely the main milk protein casein, which forms an insoluble compound with arsenic that is not absorbed into the blood. Arsenic in the form of inorganic preparations is lethal in doses of 0.05-0.1 g, and yet arsenic is present in all plant and animal organisms. (This was proved by the French scientist Orfila back in 1838.) Marine plant and animal organisms contain on average one hundred thousandths, while freshwater and terrestrial organisms contain millionths of a percent of arsenic. Microparticles of arsenic are also absorbed by the cells of the human body, element No. 33 is found in the blood, tissues and organs; especially a lot of it in the liver - from 2 to 12 mg per 1 kg of weight. Scientists suggest that microdoses of arsenic increase the body's resistance to the action of harmful microbes. Mathieu Joseph Orfila Milk is one of the antidotes for arsenic poisoning (!)
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Arsenic-Medicine Arsenic is used in dentistry to treat the pulp (tissue containing nerves, blood and lymph vessels). Salvarsan, the 606th preparation of Paul Ehrlich, a German doctor who discovered at the beginning of the 20th century, gained worldwide fame. the first effective means of combating lues (Syphilis, a venereal infectious disease). It was indeed the 606th of the arsenic preparations tested by Ehrlich. Only in the 1950s, when salvarsan was no longer used as a remedy against lues, malaria, and relapsing fever, did the Soviet scientist M.Ya. Kraft established its true formula (proved that it has a polymeric structure). Salvarsan was replaced by other arsenic drugs, more effective and less toxic, in particular its derivatives: novarsenol, miarsenol, etc. Some inorganic arsenic compounds are also used in medical practice. Arsenic anhydride As2O3, potassium arsenite KAsO2, sodium hydrogen arsenate Na2HAsO4 · 7H2O (in minimal doses) - inhibit oxidative processes in the body, increase blood formation. The same substances - as external - are prescribed for certain skin diseases. It is arsenic and its compounds that are credited with the healing effect of some mineral waters. Paul Ehrlich Salvarsan Formula
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Other uses of arsenic The most promising area of application for arsenic is undoubtedly semiconductor technology. Gallium arsenides GaAs and indium arsenides InAs acquired particular importance in it. Gallium arsenide is also important for a new direction in electronic technology - optoelectronics, which arose in 1963-1965 at the intersection of solid state physics, optics and electronics. This material helped create new semiconductor lasers. Arsenic is also used as a dopant, which gives "classical" semiconductors - Si, Ge - a certain type of conductivity. In this case, a so-called "transition layer" is created in the semiconductor, and, depending on the purpose of the crystal, it is doped in such a way as to obtain this layer at different depths. (For example, for the manufacture of diodes, it is "hidden" deeper; and if they will make solar panels, then the depth of the "transition layer" is no more than one micron.) Arsenic, as a valuable additive, is also used in non-ferrous metallurgy. So, the addition of 0.15-0.45% arsenic to copper increases its tensile strength, hardness and corrosion resistance when working in a gassed environment. In addition, arsenic increases the fluidity of copper during casting, facilitates the process of wire drawing. Arsenic is also added to lead, to some grades of bronzes, brasses, and printing alloys. And at the same time, arsenic very often harms metallurgists - its presence in ore makes production harmful. Harmful twice: firstly, for human health, and secondly, for metal - significant impurities of arsenic worsen the properties of almost all metals and alloys Arsenic sulfide compounds - orpiment and realgar - are used in painting as paints and in the leather industry as means to remove hair from the skin. In pyrotechnics, realgar is used to produce the "Greek" or "Indian" fire that occurs when a mixture of realgar with sulfur and saltpeter is burned (bright white flame). Many of the arsenic compounds in very small doses are used as drugs to combat anemia and a number of serious diseases, as they have a clinically significant stimulating effect on a number of body functions, in particular, on hematopoiesis. Laser Diode Paint Pyrotechnics
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Arsenic in the body As a trace element, arsenic is ubiquitous in wildlife. The average content of arsenic in soils is 4·10-4%, in plant ash - 3·10-5%. The content of arsenic in marine organisms is higher than in terrestrial ones (in fish, 0.6-4.7 mg per 1 kg of raw matter accumulates in the liver). The average content of arsenic in the human body is 0.08-0.2 mg/kg. In the blood, arsenic is concentrated in red blood cells, where it binds to the hemoglobin molecule. The largest amount of it (per 1 g of tissue) is found in the kidneys and liver. A lot of arsenic is found in the lungs and spleen, skin and hair; relatively little - in the cerebrospinal fluid, brain (mainly the pituitary gland), sex glands and others. Arsenic is involved in redox reactions: oxidative breakdown of complex carbohydrates, fermentation, glycolysis, etc. Arsenic compounds are used in biochemistry as specific inhibitors of enzymes to study metabolic reactions. Hands (1), arms and legs (2) with arsenic Pictures of people affected by arsenic
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Interesting facts about arsenic Did you know that… 1. In Western countries, arsenic was known mainly as a strong poison, while in traditional Chinese medicine it has been used for almost two thousand years to treat syphilis and psoriasis. Now doctors have proven that arsenic has a positive effect in the fight against leukemia. Chinese scientists have found that arsenic attacks proteins that are responsible for the growth of cancer cells. 2. Even the ancient glassmakers knew that arsenic trioxide makes glass “deaf”, i.e. opaque. However, small additions of this substance, on the contrary, lighten the glass. Arsenic is still included in the formulations of some glasses, for example, "Viennese" glass for thermometers and semi-crystal. 3. In the alpine Mono Lake in the east of the US state of California, amazing cyanobacteria live. In photosynthesis, they do not use oxygen, but arsenic, which is poisonous to almost all other life forms. Perhaps it was with them that the process of photosynthesis on our planet began, and the photosynthesis that supplies us all with oxygen and energy appeared later. Arsenic Mono Lake Collecting a sample in one of the pools at the bottom of which live arsenic-using photosynthetic cyanobacteria
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Used literature WikipediA Popular library of chemical elements Pharmaceutical Herald newspaper
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The non-metallic properties of elements are determined by the ability of atoms to “accept” electrons, i.e. exhibit oxidizing properties when interacting with atoms of other elements. Of all the elements, 22 elements have non-metallic properties, the remaining elements are characterized by metallic properties. A number of elements exhibit amphoteric properties.
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METALS AND NON-METALS In chemistry, the division of elements into metals and non-metals is accepted depending on the chemical and physical properties of simple substances (ie, on the way in which the binding of individual atoms in a simple substance is carried out). If the bond is metallic, then a simple substance is a metal with a set of properties. Non-metals are much more difficult to define because of their diversity. The criterion can be the absence of ALL (without exception) properties of metals. So, non-metals can be: - not solid substances (under standard conditions - except for Hg); - not shiny - not plastic (this is the main criterion for simple substances) (meaning the bond is not metallic)
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The strongest oxidizing agent is fluorine! It oxidizes even water and some noble gases: 2F2 + 2H2O = 4HF + O2 2F2 + Xe = XeF4 The oxidizing properties of non-metals increase in the following order: Si, B, H, P, C, S, I, Br, N, Cl, O , F
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The same regularity in the change in oxidizing properties is also characteristic of simple substances of the corresponding elements. It can be observed on the example of reactions with hydrogen: 3H2 + N2 = 2NH3 (t, catalyst) H2 + Cl2 = 2HCl (when illuminated - hϑ) H2 + F2 = 2HF (explosion in the dark) The reduction properties of non-metal atoms are rather weak and increase from oxygen to silicon: Si, B, H, P, C, S, I, Br, N, Cl, O
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Cl2 + O2 ≠ N2 + O2 = 2NO (only at high t) S + O2 = SO2 (at n.c.) Noble gases in the form of simple substances are monatomic He, Ne, Ar, etc. Halogens, nitrogen, oxygen, hydrogen as simple substances exist in the form of diatomic molecules F2, Cl2, Br2, I2, N2, O2, H2. The remaining non-metals can exist under normal conditions, both in the crystalline state and in the amorphous state. Non-metals, unlike metals, are poor conductors of heat and electricity.
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Simple substances non-metals Non-molecular structure C, B, Si These non-metals have atomic crystal lattices, therefore they have high hardness and very high melting points Molecular structure F2, O2, Cl2, N2, S8 These non-metals in the solid state are characterized by molecular crystal lattices. Under normal conditions, these are gases, liquids or solids with low melting points.
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Methods for obtaining non-metals Historically, quite a few methods have been developed for isolating non-metals from the environment. Some non-metals (simple substances) are present in the environment and can simply be extracted. These are primarily the noble gases, oxygen and nitrogen. As simple substances, deposits of carbon (graphite) and sulfur can be found. The remaining non-metals have to be extracted from complex compounds - to carry out chemical reactions.
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Chemical methods for obtaining non-metals How to choose the right reagents for a chemical reaction? There are simple rules - for the target element 1. If the non-metal is in the compound in a negative oxidation state, then to obtain a simple substance, it is necessary to use oxidizing agents: H2S + O2 → S + H2O 2KBr + Cl2 → Br2 + 2KCl HCl + KMnO4 → Cl2 + KCl + MnCl2 + H2O
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2. If the non-metal is in the compound in a positive oxidation state, then to obtain a simple substance, it is necessary to use reducing agents: SiO2 + 2Mg → Si + 2MgO Ca3(PO4)2 + 5C + 3SiO2 → 2P + + 3CaSiO3 + 5CO TeO2 + SO2 + H2O → Te + H2SO4
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Electrochemical methods Changing the oxidation state in the desired direction can also be achieved by using electric current (electrolysis): anodic oxidation (A+, anode) 2H2O - 2e- → O2 + 4H+ 2F- - 2e- → F2 (melt) cathodic reduction (K -, cathode) 2H2O + 2e- → H2 + 2OH-
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Decomposition of compounds Finally, some non-metals are formed from the decomposition of compounds. To do this, the composition of the starting material must simultaneously include both an oxidizing agent and a reducing agent: C12H22O11 (sugar) → С + H2O (pyrolysis) KClO3 → KCl + O2 (with MnO2 catalyst) AsH3 → As + H2 (Marsh reaction)
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Chemical properties of non-metals Non-metals can exhibit both oxidizing and reducing properties, depending on the chemical transformation in which they take part. The atoms of the most electronegative element - fluorine - are not able to donate electrons, it always exhibits only oxidizing properties, other elements can also exhibit reducing properties, although to a much lesser extent than metals. The strongest oxidizing agents are F2, O2, and Cl2; H2, B, C, Si, P, As, and Te show predominantly reducing properties. Intermediate redox properties have N2, S, I2.
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Interaction with simple substances 1. Interaction with metals: 2Na + Cl2 = 2NaCl, Fe + S = FeS, 6Li + N2 = 2Li3N, 2Ca + O2 = 2CaO In these cases, non-metals exhibit oxidizing properties
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2. Interaction with other non-metals: interacting with hydrogen, most non-metals exhibit oxidizing properties, forming volatile hydrogen compounds - covalent hydrides: 3H2 + N2 = 2NH3 H2 + Br2 = 2HBr Under normal conditions, these are gases or volatile liquids. Aqueous solutions of hydrogen compounds of non-metals can exhibit both basic properties (NH3, PH3) and acidic properties (HF, HCl, H2S).
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In the period with an increase in the charge of the nucleus, the acidic properties of hydrogen compounds of non-metals in aqueous solutions increase. SiH4 - PH3 - H2S - HCl Hydrosulfuric acid is a weak acid, hydrochloric acid is a strong acid. Salts of hydrosulfide acid undergo hydrolysis, salts of hydrochloric acid do not undergo hydrolysis: Na2S + H2O ↔ NaHS + NaOH (рН > 7) NaCl + H2O ≠ (рН = 7)
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In the group with an increase in the charge of the nucleus, the acidic properties and the reducing properties of hydrogen compounds of non-metals increase: HCl + H2SO4 (conc.) ≠ 2HBr + H2SO4 (conc.) \u003d Br2 + SO2 + 2H2O 8HI + H2SO4 (conc.) \u003d 4I2 + H2S + 4H2O
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interacting with oxygen, all non-metals, except fluorine, exhibit reducing properties: S + O2 = SO2 4P + 5O2 = 2P2O5 in reactions with fluorine, fluorine is an oxidizing agent, and oxygen is a reducing agent: 2F2 + O2 = 2OF2 non-metals interact with each other, a more electronegative metal plays the role of an oxidizing agent, less electronegative - the role of a reducing agent: S + 3F2 = SF6 C + 2Cl2 = CCl4
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Oxides and hydroxides of non-metals All oxides of non-metals are acidic or non-salt-forming. Non-salt-forming oxides: CO, SiO, N2O, NO Acid properties of oxides and hydroxides increase in a period, and decrease in a group: SiO2 - P2O5 - SO3 - Cl2O7 H2SiO3 - H3PO4 - H2SO4 - HClO4 Acid properties increase HNO3 H3PO4 H3AsO4 Acid properties decrease
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