Description of the presentation by individual slides:
1 slide
Slide description:
Oxygen Chemistry lesson for grade 9. Teacher: E. A. Gvozdeva. http://linda6035.ucoz.ru/
2 slide
Slide description:
General characteristics of the subgroup using the example of oxygen and sulfur Characteristics Oxygen Sulfur Chemical sign O S Placement of electrons in energy levels +8О 2е, 6е +16 S 2е, 8е, 6е Placement of electrons in orbitals in the normal state 1S22S22P4 1S22S22P63S23P43d0 Excited states No, because no unfilled orbitals 3S23P33d1 3S13P33d2 Oxidation states -2 (in OF2 +2, in H2O2-1) +2, -2, +4, +6 In the subgroup from top to bottom the radius increases, the number of energy levels increases, the metallic and reducing properties increase http: //linda6035.ucoz.ru/
3 slide
Slide description:
4 slide
Slide description:
In 1750, M.V. Lomonosov, based on his experiments, proved that the air contains a substance that oxidizes metal. http://linda6035.ucoz.ru/
5 slide
Slide description:
Oxygen was discovered by the English chemist Joseph Priestley on August 1, 1774 by decomposing mercuric oxide in a hermetically sealed vessel (Priestley directed the sun's rays at this compound using a powerful lens). 2HgO (t) → 2Hg + O2 However, Priestley initially did not understand that he had discovered a new simple substance; he believed that he had isolated one of the constituent parts of air (and called this gas “dephlogisticated air” http://linda6035.ucoz.ru/
6 slide
Slide description:
In 1771, this substance was obtained by the Swedish chemist Carl Wilhelm Scheele. He calcined saltpeter with sulfuric acid and then decomposed the resulting nitric oxide. Scheele called this gas “fiery air” and described his discovery in a publication published in 1777 (he also reported his experiment to Lavoisier.) http://linda6035.ucoz.ru/
Slide 7
Slide description:
Lavoisier Antoine Laurent in 1775 established that oxygen is part of the air and is found in many substances. Thus, the credit for the discovery of oxygen is actually shared between Priestley, Scheele and Lavoisier. http://linda6035.ucoz.ru/
8 slide
Slide description:
1. The element oxygen is in group VI, main subgroup, period II, serial number No. 8, Ar = 16. 2. Atomic structure: P11 = 8; n01 = 8; ē = 8 3. Configuration of the outer electronic layer of the neutral unexcited oxygen atom 2 s 2 2 p 4. valence II, oxidation state -2 (rarely +2; +1; -1). 4. Part of oxides, bases, salts, acids, organic substances, including living organisms - up to 65% by weight. Oxygen as an element. http://linda6035.ucoz.ru/
Slide 9
Slide description:
5. In the earth’s crust it is 49% by mass, in the hydrosphere – 89% by mass. 6. Composed of air (in the form of a simple substance) – 20-21% by volume. Air composition: O2 – 20-21%; N2 – 78%; CO2 – 0.03%, the rest comes from inert gases, water vapor, and impurities. Oxygen as an element http://linda6035.ucoz.ru/
10 slide
Slide description:
Distribution of elements in nature (by mass): Oxygen is the most common element on our planet. By weight, it accounts for approximately half of the total mass of all elements of the earth's crust. http://linda6035.ucoz.ru/
11 slide
Slide description:
Methods for producing and collecting oxygen. A) In nature: Oxygen in nature is formed during the process of photosynthesis. 6СО2 +6Н2О С6Н12О6 +6O2 2. During a thunderstorm: 3O2 2O3 http://linda6035.ucoz.ru/
12 slide
Slide description:
B) In industry: Distillation of liquefied air at t = - 1830 C under pressure. C) In the laboratory: Decomposition of some oxygen-containing substances: A) potassium perchlorate: B) with strong (above 600°C) calcination of sodium nitrate: 2NaNO3 = 2NaNO2 + O2 C) water under the influence of electric current (electrolysis): 2H2O → 2H2 + O2 D) purer oxygen is obtained by the decomposition of hydrogen peroxide H2O2 in the presence of catalytic quantities of solid manganese dioxide MnO2: 2H2O2 = 2H2O + O2. Methods for producing and collecting oxygen. 2KClO3 –t;MnO2 2KCl + 3O2 http://linda6035.ucoz.ru/
Slide 13
Slide description:
E) some higher oxides: 4CrO3 = 2Cr2O3 + 3O2; 2PbO2 = 2PbO + O2; 3MnO2 = Mn3O4 + O2. Methods for producing and collecting oxygen. http://linda6035.ucoz.ru/
14 slide
Slide description:
Methods for producing and collecting oxygen. g) potassium permanganate when heated: 2KMnO4 –t K2MnO4 + MnO2 + O2 The decomposition of this salt occurs when it is heated above 2000 C. Heating 2KMnO4 Checking the collected oxygen http://linda6035.ucoz.ru/
15 slide
Slide description:
16 slide
Slide description:
Physical properties of oxygen. tboiling= -183С; tpl = -219C; d by air = 1.1. At a pressure of 760 mm. Hg and a temperature of –183 C, oxygen liquefies http://linda6035.ucoz.ru/
Slide 17
Slide description:
Allotropy is the existence of an element in the form of several simple substances. Oxygen-O2 Ozone-O3 Gas is colorless, odorless, lighter than ozone, slightly soluble in water, has no bactericidal properties, and is not toxic. Supports the processes of respiration, combustion, oxidation, and decay. Chemically less active than ozone. Light blue gas, with a strong odor, in small concentrations with a very pleasant smell (freshness), 1.5 times heavier than oxygen, highly soluble in water. Ozone is more chemically active than oxygen and has bactericidal properties. Poisonous at concentrations greater than 10%. http://linda6035.ucoz.ru/
18 slide
Slide description:
The interaction of substances with oxygen is called oxidation. All elements react with oxygen except Au, Pt, He, Ne and Ar; in all reactions (except for the interaction with fluorine), oxygen is an oxidizing agent. 1. Unstable: O3 O2 + O 2. Strong oxidizing agent: 2KI + O3 + H2O 2KOH + I2 + O2 Discolors dyes, reflects UV rays, destroys microorganisms. With non-metals C + O2 CO2 S + O2 SO2 2H2 + O2 2H2O Chemical properties With complex substances 4FeS2 + 11O2 2Fe2O3 + 8SO2 2H2S + 3O2 2SO2 + 2H2O CH4 + 2O2 CO2 + 2H2O With metals 2Mg + O2 2MgO 2Cu + O2 –t 2CuO 4NH3+ 5O2=4NO+6H2O(complete) 4NH3+ 3O2=4N2+6H2O(not complete) http://linda6035.ucoz.ru/
Slide 19
1. Element No. 8 2. Oxygenium - Oxygen 3. Joseph Priestley 4. Karl Wilhelm Scheele 5. Antoine Laurent Lavoisier 6. Cornelius Drebbel 7. Distribution of elements in the earth's crust 8. Oxygen in nature 9. Air composition 10. Exhaled air 11 . Urban air 12. General characteristics of the element 13. Allotropy of oxygen 14. Ozone 15. Methods of gas collection, detection 16. Obtaining oxygen in the laboratory from potassium permanganate 17. Obtaining oxygen in the laboratory from hydrogen peroxide (to be continued - see the next slide) ( continued) 18. Some reactions that occur with the formation of oxygen 19. Production of oxygen in industry 20. Chemical properties of oxygen. Relation to simple substances 21. Relation of oxygen to complex substances 22. Oxidative - reduction amphotericity of oxygen 23. Conditions conducive to the occurrence and cessation of fire 24. Slow oxidation 25. Conclusions on the chemical properties of oxygen 26. Oxygen is the element of life 27. The most important function of oxygen on Earth 28. Use of oxygen 29. Oxygen cycle in nature 30. Appendix 1 “Questionnaire on the topic “Oxygen” 31. Appendix 1 “Questionnaire on the topic “Oxygen” (continued) 32. Appendix 2 “Some chemical properties of ozone. Application of ozone" 33. Author of the work The name Oxygenium was given to oxygen by A. Lavoisier C lat. oxygenium – “giving birth to acid” From Greek. oxygenes – “acid-forming” English scientist. In 1774, by decomposing mercury (II) oxide, he obtained oxygen and studied its properties 2HgO = 2Hg + O2 1733 - 1804 Swedish scientist. In 1771, he conducted experiments on the decomposition of mercury (II) oxide and studied the properties of the resulting gas. However, the results of his research were published only in 1777. 1742 - 1786 1743 - 1794 In order to test the experiments of Scheele and Priestley, in 1774 he obtained oxygen, established its nature and studied its ability to combine with phosphorus and sulfur during combustion and with metals during firing. Studied the composition of atmospheric air. Created the oxygen theory of combustion. Together with J. Meunier, he established the complex composition of water and obtained water from oxygen and hydrogen. 2H2 + O2 = 2H2O Lavoisier showed that the process of respiration is similar to the process of combustion. 1572 - 1633 Dutch alchemist and technologist. He obtained oxygen approximately 150 years before Priestley and Scheele by heating potassium nitrate: 2KNO3 = 2KNO2 + O2 His discovery was classified because the resulting gas was supposed to be used for breathing by people on submarines Oxygen ranks 1st in terms of the abundance of elements on Earth (by mass) 1 - oxygen - 49 2 - aluminum - 7 3 - iron - 5 4 - calcium - 4 5 - sodium - 2 6 - potassium - 2 7 - magnesium - 2 8 - hydrogen - 1 9 - others - 2 10 - silicon - 26 In the earth's crust - 49% (atmosphere, lithosphere, hydrosphere) In air - 20.9% (by volume) In water ( in clean water - 88.8%, in sea water - 85.8%) In sand, many rocks and minerals Composed of organic compounds: proteins, fats, carbohydrates, etc. In the human body - 62% In 1774, A. Lavoisier proved that air is a mixture of mainly two gases - nitrogen and oxygen Oxygen - 21% Nitrogen - 78% Other gases -1% Combustion of phosphorus under a bell: a - combustion of phosphorus ; b – the water level has risen by 1/5 of the volume Note Other gases (1%) include: carbon dioxide (0.03%); inert gases (mainly argon - 0.93%); water vapor The air exhaled by a person contains (in%, by volume) 1 2 3 1 – Oxygen 16% 2 – Carbon dioxide 4% 3 – The rest: nitrogen, water vapor, etc. It differs from forest air in the presence of emissions: polluting and deteriorating the air) (from vehicles (in Moscow - 90% of all pollution) from boiler plants from industrial enterprises Vehicles emit into the atmosphere: carbon dioxide CO2, sulfur dioxide SO2, nitrogen oxides NO and NO2, carbon monoxide CO, formaldehyde HCOH, as well as soot Metallurgical enterprises emit into the air: sulfur dioxide, carbon monoxide, formaldehyde, hydrogen cyanide HCN Aluminum plants hydrogen fluoride HF Pulp and paper mills hydrogen sulfide, chlorine, phenol C6H5OH and formaldehyde Chemical symbol - O Relative atomic mass: Ar = 16 Isotopes of oxygen - (99.75%), Atomic structure: (8p+ + 8n0) + 8 Nuclear charge: (+8) Electronic configuration of the atom: 1s22s2 2p4 A typical non-metal. Strong oxidizing agent (second only to fluorine in electronegativity) Valence possibilities: in compounds there are usually 2 valentines, less often - 3-. x, (4-x) valentene Possible oxidation states: - 2, - 1, 0, + 2, (+4) (the most characteristic oxidation states: 0, - 2) The chemical element oxygen forms two simple substances, the allotrope is oxygen O2 and ozone O3 Some comparative data Oxygen - O2 Formed in nature During photosynthesis Light Physical state (vol.) Color Odor Mr ρ (in liquid. composition, g/cm3) t pl., o C t boil, o C Relation to water Physiological activity Biological activity Chemical activity (vol.) (oxidizing capacity) Role in nature 6CO2+ 6H2O = C6H12O6 + 6O2 Ozone - O3 From O2 (during a thunderstorm; air UV-Sun) 3O2<═>2O3 - Q Gas Colorless (g) Odorless 32 1.118 - 218.8 - 182.9 Poorly soluble Non-toxic Within normal limits Gas t, or UV Blue (g) O3 = O2 + O Harsh, irritating 48 1.78 - 192, 5 - 111.9 Soluble 10 times better Toxic Strong antiseptic Low activity (=) (Strong o-l at t) Breathing, rotting, combustion Stronger oxidizing agent (due to atomic oxygen) Protective screen of the Earth from UV radiation of the Sun Ozone is formed in the atmosphere at an altitude of 10-30 km under the influence of UV radiation on air and during lightning discharges The simplest ozonator Liquid ozone has the appearance of indigo A wire is inserted inside a wide glass tube. The outside of the tube is wrapped with another wire. If a voltage of several thousand volts is applied to the ends of two wires and oxygen is passed through the tube, the gas coming out of it will contain several percent ozone. a – displacement of water (above water); b – air displacement; 1 – flashed smoldering splinter 2 KMnO4 = K2MnO4 + MnO2 + O2 KMnO4 – potassium permanganate; 1- glass wool 2 H2O2 = 2 H2O + O2 1 – dropping funnel with hydrogen peroxide solution 2 – manganese (IV) oxide powder – MnO2 (used in this reaction as a catalyst) 3 – Wurtz flask Reaction conditions – heating (t) 2 KMnO4 = K2MnO4 + MnO2 + O2 2KClO3 = 2Kl + O2 2HgO = 2Hg + O2 3PbO2 = Pb3O4 + O2 2KNO3 = 2KNO2 + O2 Reaction conditions – presence of catalyst (K) 2H2O2 = 2H2O + O2 (K – MnO2) Reaction conditions – action of electric current ( (electrolysis solution) 2H2O = 2H2 + O2) Oxygen is obtained from air by gas rectification. The air is cooled to approximately – 200 0С and liquefied under pressure. Next, the liquid air is subjected to distillation. Liquid nitrogen evaporates at – 196 OC (t boiling point of liquid nitrogen) Liquid oxygen evaporates at - 183 OS (boiling point of liquid oxygen) Oxygen gas is stored in blue-painted steel cylinders under a pressure of 1 - 1.5 MPa 1. Relation to simple substances a) metals b) non-metals Oxidation reactions accompanied by the release of heat and light, is called combustion (substances ignite in this case) t 3Fe + 2O2 ═ Fe3O4 + Q (FeO · Fe2O3) t C + O2 ═ CO2 + Q t S + O2 ═ SO2 + Q t 2Mg + O2 ═ 2MgO + Q t 4P + 5O2 ═ 2P2O5 + Q Oxidation reactions without combustion t 2Cu + O2 ═ 2CuO + Q Ignition of copper does not occur t N2 + O2<═> 2 NO Q In oxidation reactions, as a rule, oxides are formed 2. Relation to complex substances When hydrocarbons are completely burned, oxides are formed - carbon dioxide and water: t CH4 + 2O2 = CO2 + 2H2O + Q methane t 2C2H2 + 5O2 = 4CO2 + 2H2O + Q acetylene With incomplete combustion of hydrocarbons (for example, with a lack of oxygen O2), carbon monoxide CO and soot C are also formed: t 2CH4 + 3O2 = 2CO + 4H2O + Q t CH4 + O2 = C + 2H2O + Q O - as an oxidizing agent: O0 + 2 → O–2 (1) (usually) O - as a reducing agent: O0 - 2 → O+2 (2) (for example, in a reaction with F2) 2Mg + O2 = 2MgO C + O2 = CO2 2F2 + O2 = 2F2O (1) (1) (2) Conditions for Conditions for stopping the occurrence of combustion combustion 1. Heating the flammable substance to the ignition temperature 2. Access to oxygen 1. Stop oxygen access to the combustible substance 2. Cool the substance below the ignition temperature Slow oxidation is a chemical process of slow interaction of a substance with oxygen without igniting the substance. During this process, heat is released gradually and the substance is not heated to the ignition temperature. Examples: In the processes of oxidation (aerobic decomposition) of certain food substances and metabolic products in the cells and tissues of living organisms, the energy needed by the body is released. In the process rotting (oxidation) of manure releases heat, etc. Reactions of substances with oxygen are oxidation reactions. Oxidation reactions are an integral part of oxidation-reduction reactions (ORR). The predominant function of oxygen is oxidative. At room temperature O2 is inactive, at high temperature it is a strong oxidizing agent. Oxidation reactions, as a rule, produce oxides (EO) Oxidation reactions accompanied by ignition of a substance, combustion reactions Combustion reactions are always exothermic reactions (+ Q) Slow oxidation is a chemical process of slow interaction substances with oxygen without ignition of the substance Oxygen is part of water, which makes up most of the mass of living organisms and is the internal environment for the life of cells and tissues Oxygen is part of the biologically important molecules that form living matter (proteins, carbohydrates, fats, hormones, enzymes, etc. .) Oxygen in the form of a simple substance O2 is necessary as an oxidizing agent for the occurrence of reactions that give cells the energy necessary for life. Oxygen on Earth is oxidizing agent No. 1, because it ensures the occurrence of such important processes as: respiration of all living organisms, decay of organic matter (in addition influence of fungi and bacteria) combustion of substances Oxygen is used in its pure form: In metallurgy - in the production of cast iron, steel, non-ferrous metals (to intensify oxidation processes) In many chemical industries As a liquid oxidizer for rockets When cutting and welding metals and alloys In medicine - for preparation of medicinal water and air baths, medicinal cocktails In medicine - in oxygen pillows In pure form and as part of mixtures: On spaceships, submarines in scuba diving, at high altitudes In the air: For burning fuel (in car engines, diesel locomotives, motor ships; at thermal power plants, in many industries, etc. ) Oxygen is consumed in nature for oxidation processes (respiration, decay, combustion) The mass of oxygen in the air is replenished during the process of photosynthesis light 6CO2 + 6 H2O = C6H12O6 +6O2 Appendix 1 “Questionnaire for the topic “Oxygen” Name the eighth element of the “Periodic Table of Chemical Elements” D.I. Mendeleev" (slide No. 4) 2. By whom and when was oxygen discovered? (slides No. 6 - 9) 3. Why was element No. 8 named oxygen? (slide number 5) 4. Where and in what form (free or bound) is oxygen found in nature? (slides No. 10 - 11) 5. What is the composition of atmospheric air? (slide number 12) 6. What is the composition of the air exhaled by a person? (slide No. 13) 7. List the air pollutants you know? (slide No. 14) 8. Characterize oxygen as a chemical element (slide No. 15) 9. What allotropic modifications of oxygen do you know? (slide No. 16) 10. What remarkable properties does ozone have, unlike oxygen? What properties of ozone do people use in their practical activities? (slides No. 16-17, 35) 11. What physical properties of oxygen are the methods for collecting it based on? How can oxygen be detected? (slide number 18) 1. Appendix 1 “Questionnaire on the topic “Oxygen” (continued) 12. How is oxygen obtained in the laboratory? (slides No. 19 - 21) 13. How is oxygen obtained in industry? (slide number 22) 14. List the most important chemical properties of oxygen. What is oxidation? What products are typically obtained in the oxidation reactions of substances with oxygen? (slides No. 23 - 24) 15. What is meant by the oxidation-reduction abilities of oxygen? What functions predominate in it? Give examples (slide number 25) 16. What conditions contribute to the onset and cessation of combustion? Why is the rate of combustion of substances in oxygen higher than in air? (slide number 26) 17. How do the processes of combustion and slow oxidation differ? (slide number 27) 18. What conclusions can be drawn from the chemical properties of oxygen? (slide No. 28) 19. Why is oxygen considered the “elements of life”? (slide number 29) 20. What is the most important function of oxygen on Earth? (slide number 30) 21. List the uses of oxygen (slide number 31) 22. How do you understand the essence of the oxygen cycle in nature? (slide number 32) Appendix 2 “Some chemical properties of ozone. Application of ozone The oxidative activity of ozone O3 is noticeably higher than that of oxygen O2. For example, already at rev. u. it oxidizes many low-active simple substances (Ag, Hg, etc.): 8Ag + 2O3 = 4Ag2O + O2 When exposed to alkali metals and some alkalis, it forms ozonides: K + O3 = KO3 4KOH + 4O3 = 4KO3 + O2 + H2O Qualitatively and quantitatively Ozone is determined using the following reaction: 2KI + H2O + O3 = 2KOH + I2 + O2 Reduced iodine is detected using starch paste. Ozone is used to disinfect water and air, deodorize food, as a bactericidal agent in the treatment of certain human diseases, bleach fabrics and oils, and in various chemical syntheses. The author of the work is Belyaeva Galina Bronislavovna, chemistry teacher at GOU Secondary School No. 1212 with in-depth study of the German language in Moscow
Oxygen. Oxygen and its properties. Topic: "Oxygen". The volume of air in the room. Methods for obtaining oxygen. Reactive oxygen species. Presentation on the topic: oxygen. Use of oxygen. This Air is Invisible. Allotropy of oxygen. Application of polymer materials. Oxygen in human life. Oxygen and its effect on the body.
Clean air is the key to health. General characteristics of the elements of the oxygen subgroup. Application of Biogas plants. Application of electronic educational resources in the educational process. Application of heat accumulators. Lesson topic: “Chemical properties of oxygen. In the format of training rooms. Oxygen is friend or foe. The children's room is the territory of happiness.
Thermite and propane-oxygen welding. Oxygen production, concept of catalysts. This substance is second only to oxygen in importance for human life. Oxygen 7th grade. Chemistry 7th grade oxygen. Ready-made movement therapy. Chemical properties of oxygen. The use of oxygen and its biological role.
Resources for oxygen and complex life support. Oxygen. Ozone is an allotropic modification of oxygen. Basic technological requirements for cladding gypsum plasterboard. How to obtain more and cheaper oxygen in a school laboratory.
To use presentation previews, create a Google account and log in to it: https://accounts.google.com
Slide captions:
Oxygen
Position of oxygen in p.s. Electronic structure. 2nd period, 2nd row, 6-A group The ancestor of the main subgroup of the 6th group. “Chalcogens” - giving birth to ores (O, S, Se, Te, Po) O 8 15.9994 2s 2 2p 4 Oxygen
Distribution of oxygen in nature. Oxygen is the most abundant element on our planet.
Oxygen accounts for approximately half of the total mass of the earth's crust. In soils, groundwater, river and sea waters, oxygen acts as a real geochemical dictator.
Physical properties of oxygen. Gas without color, smell and taste; In the liquid state it has a light blue color, in the solid state it is blue; Oxygen gas is more soluble in water than nitrogen and hydrogen.
Chemical properties of oxygen. A strong oxidizing agent, it interacts with almost all elements, forming oxides. Oxidation state −2. As a rule, the oxidation reaction proceeds with the release of heat and accelerates with increasing temperature. Example of reactions occurring at room temperature: 4K + O2 → 2K2O 2Sr + O2 → 2SrO Oxidizes compounds that contain elements with less than the maximum oxidation state: 2NO + O2 → 2NO2 Oxidizes most organic compounds: CH3CH2OH + 3O2 → 2CO2 + 3H2O Oxygen does not oxidize Au and Pt, halogens and inert gases. Reacts with other non-metals, forming oxides: S+O2 →SO2 C+O2 →CO2 Actively interacts with alkali and alkaline earth metals to form oxides and peroxides: 2Na+O2 →Na2O2 Reacts with other metals when heated, releasing a large amount of heat and light: 2 Mg+O2 →2MgO
Obtaining oxygen in the laboratory. Most often, oxygen is obtained by heating substances (which contain oxygen in bound form) such as potassium permanganate (potassium permanganate), potassium chlorate (Berthollet salt), potassium nitrate (saltpeter), hydrogen peroxide: 2 KMnO 4 = K 2 MnO 4 + MnO 2 + O 2 potassium permanganate heating potassium manganate manganese dioxide oxygen 2 KClO 3 = 2 KCl + 3 O 2 potassium chlorate heating potassium chloride oxygen
2 KNO 3 = 2 KNO 2 + O 2 potassium nitrate heating potassium nitrite oxygen 2 H 2 O 2 = 2 H 2 O + O 2 hydrogen peroxide catalyst oxygen
Oxygen collection by water and air displacement methods
Oxygen cycle in nature.
Photosynthesis
Discovery of oxygen. He obtained oxygen in many ways: by calcining mercuric oxide (as Priestley and Lavoisier did), heating mercury carbonate and silver carbonate, etc. Undoubtedly, Scheele was the first (1772) to “hold in his hands” pure oxygen.
Scheele manuscript page
Joseph Priestley (Joseph Priestley, 1733-1804) 2 HgO = 2 Hg + O 2 mercuric oxide heating mercury oxygen
Antoine Lavoisier (Lavoisier, Antoine Laurent, 1743-1794) Repeating Priestley's experiments, Lavoisier concluded that atmospheric air consists of a mixture of “vital” (oxygen) and “suffocating” (nitrogen) air and explained the combustion process by combining substances with oxygen. Early in 1775, Lavoisier reported that the gas obtained by heating red oxide of mercury was “air as such, unchanged (except that) ... it is purer, more respirationable.”
Use of oxygen.
Thank you for your attention!
Slide presentation
Slide text: Presentation prepared by Roxana Smirnova, 9th grade student of the Lyceum of Otradnoye
Slide text: Oxygen as an element. 1. The element oxygen is in group VI, main subgroup, period II, serial number No. 8, 2. Atomic structure: P11 = 8; n01 = 8; ē = 8 valence II, oxidation state -2 (rarely +2; +1; -1). 3. Part of oxides, bases, salts, acids, organic substances, including living organisms - up to 65% by weight.
Slide text: Oxygen as an element. Oxygen is the most common element on our planet. By weight, it accounts for approximately half of the total mass of all elements of the earth's crust. Air composition: O2 – 20-21%; N2 – 78%; CO2 – 0.03%, the rest comes from inert gases, water vapor, and impurities. 4. In the earth's crust it is 49% by mass, in the hydrosphere - 89% by mass. 5. Composed of air (in the form of a simple substance) – 20-21% by volume. 6. Included in most minerals and rocks (sand, clay, etc.). Composed of air (in the form of a simple substance). 7. A vital element for all organisms, found in most organic substances, involved in many biochemical processes that ensure the development and functioning of life. 8. Oxygen was discovered in 1769-1771. Swedish chemist K.-V. Scheele
Slide text: Physical properties. Oxygen is a chemically active non-metal and is the lightest element from the group of chalcogens. The simple substance oxygen under normal conditions is a colorless, tasteless and odorless gas, the molecule of which consists of two oxygen atoms, for which reason it is also called dioxygen. Liquid oxygen is light blue in color, while solid oxygen is light blue crystals.
Slide text: Chemical properties. With non-metals C + O2 CO2 S + O2 SO2 2H2 + O2 2H2O With complex substances 4FeS2 + 11O2 2Fe2O3 + 8SO2 2H2S + 3O2 2SO2 + 2H2O CH4 + 2O2 CO2 + 2H2O With metals 2Mg + O2 2MgO 2Cu + O2 –t 2CuO Interaction substances with oxygen is called oxidation. All elements react with oxygen except Au, Pt, He, Ne and Ar; in all reactions (except for the interaction with fluorine), oxygen is an oxidizing agent. 1. Unstable: O3 O2 + O 2. Strong oxidizing agent: 2KI + O3 + H2O 2KOH + I2 + O2 Discolors dyes, reflects UV rays, destroys microorganisms.
Slide text: Methods of obtaining. Industrial method (distillation of liquid air). Laboratory method (decomposition of some oxygen-containing substances) 2KClO3 –t ;MnO2 2KCl + 3O2 2H2O2 –MnO2 2H2O + O2
Slide text: Checking the collected oxygen. Obtaining 3O2 2O3 During a thunderstorm (in nature), (in the laboratory) in an ozonizer of potassium permanganate when heated: 2KMnO4 –t K2MnO4 + MnO2 + O2 The decomposition of this salt occurs when it is heated above 2000 C.
Slide text: Application of oxygen: It is widely used in medicine and industry. During high-altitude flights, pilots are provided with special oxygen devices. For many pulmonary and heart diseases, as well as during operations, oxygen is given to inhale from oxygen cushions. Submarines are supplied with oxygen in cylinders. The combustion of loose combustible material impregnated with liquid oxygen is accompanied by an explosion, which makes it possible to use oxygen in blasting operations. Liquid oxygen is used in jet engines, in autogenous welding and metal cutting, even under water.
