“Iodine in the human body” - And if there is not a single line left, you have a clear iodine deficiency. The human body consists of 60% water, 34% organic matter and 6% inorganic matter. Iodine requirement in mcg/day. There are two tests to determine iodine deficiency. Discovery of iodine. Iodine is the only halogen that is in a solid state under normal conditions.
“Trace element iodine” - Iodine normalizes the functioning of the nervous system. Iodine is involved in the proliferation of cells of the osteochondral system. Iodine regulates the functioning of the thyroid gland and restores the hormonal balance of the body. Iodine improves lipid metabolism. Iodine takes part in the synthesis of the hormones triiodothyronine and thyroxine. Iodine ensures the growth of cells of the nervous system and improves neuropsychic development.
“Iodine in the body” - Lack of iodine in the body can lead to: Signs of iodine deficiency: Questionnaire Practical experience Chemical experiment Titration Comparison and analysis. Do not use loose iodized salt. Hypothesis. Research methods. Analyze the situation with iodine deficiency at school and make recommendations on dietary diversity.
"Halogens" - Chlorine has been used in medicine. 24 artificial isotopes of astatine. Heavy dark red liquid. Fluorine is part of polymers. Chlorine. Look at the drawing. Iodine content. Fluorine. Chlorine belongs to the group of asphyxiants. Electrolysis. Preparation of chlorine in the laboratory. Bromine is stored in bottles with ground glass stoppers.
“Halogen elements” - Metabolism. Solve the problem. Production of halogens. Being in nature. Bromine. Fluorine and chlorine. Write an equation for the reaction. Position of halogens in the table. Biological significance. Industrial use.
“Characteristics of halogens” - Occurrence in nature. Chemical properties. Reducing agent. Halogens. Oxidizer. Physical properties. Discovery of halogens. Active halogen. General characteristics of halogens. Volatile hydrogen compounds.
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Evgenia Andreevna Kazantseva, chemistry teacher at Municipal Educational Institution School No. 12 with in-depth study of individual subjects City of Zhukovsky Comparative characteristics of halogens https://sites.google.com/site/kazancevaevgenia/home
Goal: to expand the understanding of analogue elements of the Periodic Table using the example of a subgroup of halogens Objectives: To introduce students to the history of the discovery of halogens To compare the structure of halogen atoms, identifying similarities and differences To compare the physical properties and chemical activity of halogens To give an idea of the role of halogens in the body
Discovery of halogens Fill out the table: Name of halogen What does the name mean Date of discovery Who discovered the reaction equation Fluorine Chlorine Bromine Iodine Astatine
Discovery of fluorine Fluorine (F 2) – from the Greek. “fluorine” - destructive was discovered in 1866 by the French chemist Henri Moissan by electrolysis of a mixture of liquid anhydrous HF and potassium hydrodifluoride KHF 2 in a platinum vessel: 2HF →H 2 + F 2 cathode anode In 1906, Moissan was awarded the Nobel Prize for the discovery of the element fluorine and introduction into practice of an electric furnace named after him
Discovery of chlorine Chlorine Cl 2 from the Greek. “chloros” - yellow-green 1774 Swedish pharmacist Karl Wilhelm Scheele “I placed a mixture of black magnesia with muric acid in a retort, to the neck of which I attached a bubble devoid of air, and placed it in a sand bath. The bubble was filled with gas, which had a yellow-green color and a piercing odor.” Reaction equation: MnO 2 + 4HCl Cl 2 + MnCl 2 + 2H 2 O
Discovery of bromine Bromine (Br 2) from the Greek. “bromos” - foul-smelling It was discovered in 1826 by the French chemist (24-year-old laboratory assistant) Antoine-Jerome Balard. The effect of chlorine on the brines of the salt marshes of France according to the reaction: 2NaBr + Cl 2 → 2NaCl + Br 2
Discovery of iodine Iodine (I 2) from Greek. “iodes” - purple Was discovered in 1811 by the French chemist-technologist and pharmacist Bernard Courtois in seaweed ash Reaction equation: 2 NaI + H 2 SO 4 → Na 2 SO 4 + I 2
Discovery of astatine Astatine (At 2) from the Greek. “astatos” - unstable It was obtained in 1940 artificially by irradiating bismuth with alpha particles by University of California scientists D. Corson and K.R. Mackenzie
Structure of halogen atoms F + 9)) 2 7 Cl +17))) 2 8 7 Br + 35)))) 2 8 18 7 l + 53))))) 2 8 18 18 7 The charge of the nucleus increases The radius of the atom increases Quantity valence electrons is 7 The attraction of valence electrons to the nucleus decreases The ability to donate electrons increases Non-metallic properties weaken The oxidizing ability decreases
Physical properties of simple halogen substances Bromine Iodine Chlorine Astatine
Sublimation of iodine Crystalline iodine has the ability, when heated, to pass from a solid to a gaseous state, bypassing the liquid state (sublimation), turning into violet vapor. Experiment: sublimation of iodine Iodine vapor
Comparison of the physical properties of simple halogen substances F 2 light yellow gas Cl 2 yellow-green gas Br 2 red-brown liquid I 2 dark gray crystals with a metallic luster At 2 black-blue crystals Color intensity increases Density increases Melting and boiling points increase
Chemical properties of fluorine Interacts with all metals, releasing a large amount of heat: with aluminum: 3 F 2 + 2 Al → 2 AlF 3 + 2989 kJ with iron: 3 F 2 + 2Fe → 2FeF 3 + 1974 kJ When heated, it interacts with many non-metals, except oxygen, nitrogen and diamond with hydrogen: F 2 + H 2 → 2HF 2 +547 kJ with silicon: 2 F 2 + Si → SiF 4 + 1615 kJ Oxidizes other halogens: chlorine: F 2 + Cl 2 → 2ClF bromine: F 2 + Br 2 → 2BrF iodine: F 2 + I 2 → 2lF
Chemical properties of fluorine Reacts when irradiated even with inert gases Xe + F 2 → Xe F 2 + 152 kJ Interacts with complex substances: with water: 2F 2 + 2H 2 O → 4HF + O 2 with alkalis: 2F 2 + 2NaOH → 2NaF + H 2 O + OF 2 with silicon oxide: 2F 2 + SiO 2 → SiF 4 + O 2
Chemical properties of bromine The chemical activity of bromine is less than that of fluorine and chlorine, but quite high. With metals: Interaction of bromine with aluminum 3Br 2 + 2Al → 2AlBr 3 With non-metals: Interaction with hydrogen Br 2 + H 2 → 2 HBr Interaction with silicon 2 Br 2 + Si → SiBr 4 When bromine is dissolved in water, bromine water is formed, which is used in organic chemistry.
Chemical properties of iodine The chemical activity of iodine is even lower than that of bromine. With metals only when heated: Interaction of iodine with iron I 2 + Fe → FeI 2 Interaction of iodine with aluminum 3I 2 + 2Al → 2AlI 3 With non-metals: Interaction with hydrogen when heated I 2 + H 2 → 2 H I - Q
Conclusion: the chemical activity of halogens decreases from fluorine to iodine, therefore a halogen with a lower atomic number can displace a halogen with a higher atomic number from its compounds with hydrogen and metals: Interaction of chlorine water with halides 2KI + Cl 2 → 2KCl + I 2 NaCl + Cl 2 → 2NaBr + Cl 2 → 2NaCl + Br 2
Qualitative reactions to halide ions Qualitative reactions to chlorides, bromides and iodides - formation of insoluble silver halides: NaCl + AgNO 3 → AgCl↓ + NaNO 3 white cheesy precipitate NaBr + AgNO 3 → AgBr↓ + NaNO 3 yellowish cheesy precipitate NaI + AgNO 3 → AgI↓ + NaNO 3 yellow cheesy sediment
Halogens and health Fill out the table: Name of halogen Role in the body Deficiency Excess Source
Fluoride and health (daily norm 2-3 mg) Role in the body ensures the strength of bone tissue, proper growth of the skeleton, hair and nails, increases the resistance of teeth to carious diseases, takes part in hematopoiesis, protects against osteoporosis Disadvantage: caries (destruction of tooth enamel) , weakening bones, hair loss Excess: fluorosis (spotting of tooth enamel), slow growth, skeletal deformation Sources of fluoride Water Sea fish Walnuts Tea
Chlorine and health (daily allowance 2g) Role in the body: Formation of hydrochloric acid, maintaining water-electrolyte balance, removing toxins and carbon dioxide from the body, breaking down fats Disadvantage: muscle weakness, drowsiness, lethargy, weakened memory, loss of appetite, dry mouth , loss of teeth and hair Excess: water retention in tissues, increased blood pressure, pain in the head and chest, dyspeptic disorders, dry cough, lacrimation, pain in the eyes Sources of chlorine Beetroot Legumes Cereals Table salt
Bromine and health (daily norm 0.5-2 mg) Role in the body: takes part in the regulation of the nervous system, affects the functions of the gonads, affects the processes of excitation and inhibition in the brain Disadvantage: insomnia, decreased growth of red blood cells in blood. Excess: skin disease - bromoderma, disruption of the nervous system, apathy, drowsiness, memory loss Sources of bromine
Iodine and health (daily norm 100-200 mcg) Role in the body: Participation in the synthesis of thyroid hormones, creation of patrol cells in the blood - phagocytes. Excess: hyperthyroidism - increased metabolism, increased heart rate, excitability Deficiency: hypothyroidism - decreased thyroid function (decreased metabolism, decreased body temperature, weakness), Graves' disease, mental retardation Sources of iodine Squid Persimmon Tomatoes Sea fish Carrots Sea kale
2 l e l e s o m d i o v o a t s s o v a v d i d i n i a s o l e t t y o c i s l i t l l l l y y l e b l e g o l g o r b e d s i r e o x e n e l e b r a m d l t i g a t w o d e r 1 2 3 4 8 10 12 9 13 17 16 5 11 6 7 19 18 14 n 15 2 w 2 (horizontal). NaI is the name of substance 4 (horizontally). Cl 2 + ... →FeCl 3 5 (horizontal). F 2 +… →HF+O 2 10 (horizontal). The role of HCl in the reaction: MnO 2 + 4HCl → MnCL 2 + Cl 2 + 2H 2 O 12 (horizontal). The role of bromine in the reaction: Br 2 + 2KI → 2KBr + I 2 13 (horizontal). A halogen, which under normal conditions is a liquid 1 5 (horizontally). A natural compound with the composition NaCl 1 7 (horizontal). The scientist who discovered chlorine 18 (horizontal). Precipitate color AgI 19 (horizontal). Metal whose nitrate is used for the determination of halogens 1 (vertical). The highest oxidation state of halogens (except fluorine) is 2 (vertical). Halogen, the crystals of which have a black-violet color with a metallic luster 3 (vertical). The number of atoms in the molecules of simple halogen substances is 6 (vertical). Radioactive halogen 7 (vertical). The second name for hydrochloric acid is 8 (vertical). The oxidation state of simple substances - halogens is 9 (vertical). Element VII A of group 11 (vertical). The color of the precipitate during the qualitative determination of chlorine ions Cl ¯ 1 4 (vertical). Br 2 + ... →CuBr 2 1 6 (vertical). Name of salt of hydrochloric acid
Homework § 31, exercises 3,4,6,7,9,13 (p. 151). When preparing your homework, I suggest you look at my website: https://sites.google.com/site/kazancevaevgenia/home There you will find control questions that you need to pay attention to when studying halogens; links to additional materials on the properties of chlorine and other halogens. See you on the site!
Materials used http://ru.wikipedia.org - information about halogens, 10/15/2010, 10/31/2010 http://ru.wikipedia.org - portrait of Bernard Courtois, 10/15/2010 http://ru.wikipedia.org - photo of iodine, 10/17/2010 http://www.baby24.lv/ru/info-h/412 - information about the role of halogens in the body, 10/31/2010, 11/01/2010 http://images.yandex.ru - pictures, photos, portraits 10.28.2010, 10.29.2010, 10.31.2010, 11.01.2010 http:/, files.school-collection.edu.ru - video experiences, 10.20.2010, 10.23.2010, 10.30.2010
Used literature Yu.V. Galichkina, Entertaining chemistry in lessons in grades 8-11, Uchitel Publishing House, 2005. V.V.Eremin, N.E.Kuzmenko, A.A.Drozdov “Chemistry-9th grade”, publishing house “Peace and Education”, 2005 N.E.Kuzmenko, V.V.Eremin, V.A. Popkov "Principles of Chemistry"
Slide 2
Goals and objectives of the essay
Fluorine is quite common in nature. Its percentage in the earth's crust approaches the content of elements such as nitrogen, sulfur, chromium, manganese and phosphorus. And at the same time, the compounds of these elements are widely described in any chemical literature, while only small reference data are given about fluorine and its compounds. The objectives of my essay are as follows: To explore the history of the discovery of fluorine and its distribution in nature. Describe the physical and chemical properties of fluorine. Collect data on fluoride compounds. Study the use of fluorine and its compounds.
Slide 3
Historical reference
The existence of the element, which was later named fluorine (from the Greek “fluoros” - destruction, death), was suspected by many chemists of the late 18th - early 19th centuries, but it was not possible for a long time to obtain it in its pure form due to its extraordinary activity. One of the most interesting fluorine compounds, hydrofluoric acid HF, was obtained in 1771 by the famous Swedish chemist K. Scheele, who suggested that this acid contained a new chemical element. But more than a hundred years passed before chemists finally isolated this element. This happened in 1886; the discoverer of free fluorine was the French chemist A. Moissan.
Slide 4
Origin of fluorine
The name “fluorine”, proposed by A. Ampere in 1810, is used only in Russian; in many countries the name “fluor” is used.
Slide 5
Being in nature
Fluorine is distributed quite widely in nature. Its content in the earth's crust is 6.25.10-2% of the total mass. Free fluorine actually does not occur in nature. The bulk of fluorine is distributed among various rocks. Of the minerals containing fluorine, the most important are fluorspar (fluorite) CaF2, apatite Ca10 (F,CI)2 (PO4)6, cryolite Na3 AlF6.
Slide 6
Physical properties of fluorine
Fluorine is a poisonous gas. Under normal conditions, fluorine is a pale yellow gas with a sharp, characteristic odor reminiscent of chlorine and ozone, detectable even with traces of fluorine. In liquid form, fluorine is canary yellow in color. The fluorine molecule is diatomic (F2); the heat of its dissociation is not precisely determined and, depending on the measurement method, ranges from 51 to 73 kcal/mol.
Slide 7
Chemical properties of fluorine
Fluorine in its compounds is only negatively monovalent. Already in the cold, fluorine is energetic: it combines with bromine, iodine, sulfur, phosphorus, silicon, and most metals, and these reactions are often accompanied by an explosion. The simplest means of extinguishing fires - water - burns in fluorine with a light brown flame. Fluorine forms organofluorine compounds with organic substances.
Slide 8
Poisoning with fluorine and its compounds
Acute fluoride poisoning in industrial conditions is observed extremely rarely, only in accidents. At high concentrations of hydrogen fluoride in the air, irritation of the eyes and mucous membrane of the larynx and bronchi, lacrimation, salivation, and nosebleeds occur. Hydrofluoric acid has a cauterizing effect on the skin, causing the formation of difficult-to-heal ulcers. Fluoride compounds inhibit the enzymes enolase, cholinesterase and others, and also cause disturbances in calcium and phosphorus metabolism. Treatment for poisoning with fluoride compounds is to drink a 0.5 - 1% solution of calcium chloride with a mixture of burnt magnesia, lavage the stomach with the same mixture; intravenous administration of 10% calcium chloride solution (10 ml).
Slide 9
Safety precautions
For individual protection from fluoride compounds, rubber gloves and shoes, overalls, gas masks, dust respirators, etc. are used. Workers engaged in the production of fluorine, hydrofluoric acid, organofluorine compounds, in the production and use of beryllium fluoride and beryllium fluoroxide are subject to periodic medical examination once every 6 months, and in some industries – once a year. Additional special nutrition is prescribed for the production of superphosphate, cryolite, fluorine derivatives and fluorine-containing salts. B vitamins, calcium ascorbate, and foods rich in calcium are recommended.
Slide 10
Application
The most widely used compounds are fluorides: oxygen fluoride is used in jet technology as the most powerful oxidizing agent after ozone, hydrofluoric acid is used as a solvent and for etching glass, boron fluoride is used in liquid form as an oxidizer of liquid jet fuel, for the fluorination of uranium compounds in the nuclear industry, etc. etc., uranium hexafluoride – for isolating the radioactive isotope of uranium in nuclear technology
Slide 11
Application
sulfur hexafluoride - as a gas for insulating high-voltage installations, sodium fluoride - to combat pests of agricultural plants, cryolite - in the production of aluminum, fluorspar is widely used in metallurgy and in the manufacture of enamels, elemental fluorine is used in liquid form as an oxidizer for jet fuel and for disinfection of drinking water, freons are used as refrigerants in refrigeration units.
Slide 12
Fluoride in the body
Fluorine is a constant component of plant and animal organisms. When fluoride levels in water increase or decrease, illnesses occur in freshwater and terrestrial animals; for example, when the fluorine content in water is more than 0.00005%, fluorosis can develop - a disease accompanied by spotting of enamel and brittle teeth. When the fluoride content does not reach this level, dental caries occurs (destruction of tooth enamel and dentin). Fluorine enters a living organism, in addition to drinking water, with food products, which contain on average about 0.02-0.05 mg% fluoride.
Slide 13
Receipt
Fluorine is obtained by electrolysis of the melt of acidic potassium trifluoride KF·2HF, since fluorine has extremely high reactivity. When processing natural phosphates into artificial fertilizers, fluorine compounds are obtained as by-products, which are used in liquid form as an oxidizer of liquid jet fuel for the fluorination of uranium compounds in the nuclear industry.
Slide 14
Conclusion
As a result of my work on the topic of the essay, I became acquainted with the properties of fluorine and its compounds in the process of studying various literature. The variety of inorganic and organic fluorine compounds and the wide range of their applications in everyday life was a revelation to me. Of course, it is a pity that my work is limited to purely theoretical content, but I hope that these materials will be of interest to other children who will study chemistry.
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Presentation on the topic: Fluorine
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Aims and objectives of the abstract Fluorine is quite common in nature. Its percentage in the earth's crust approaches the content of elements such as nitrogen, sulfur, chromium, manganese and phosphorus. And at the same time, the compounds of these elements are widely described in any chemical literature, while only small reference data are given about fluorine and its compounds. The objectives of my essay are as follows: To explore the history of the discovery of fluorine and its distribution in nature. Describe the physical and chemical properties of fluorine. Collect data on fluorine compounds. Study the use of fluorine and its compounds.
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Historical background Many chemists of the late 18th and early 19th centuries guessed about the existence of the element, which was later named fluorine (from the Greek “fluoros” - destruction, death), but it was not possible for a long time to obtain it in its pure form due to its extraordinary activity. One of the most interesting fluorine compounds, hydrofluoric acid HF, was obtained in 1771 by the famous Swedish chemist K. Scheele, who suggested that this acid contained a new chemical element. But more than a hundred years passed before chemists finally isolated this element. This happened in 1886; the discoverer of free fluorine was the French chemist A. Moissan.
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Occurrence in nature Fluorine is distributed quite widely in nature. Its content in the earth's crust is 6.25.10-2% of the total mass. Free fluorine actually does not occur in nature. The bulk of fluorine is distributed among various rocks. Of the minerals containing fluorine, the most important are fluorspar (fluorite) CaF2, apatite Ca10 (F,CI)2 (PO4)6, cryolite Na3 AlF6.
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Physical properties of fluorine Fluorine is a poisonous gas. Under normal conditions, fluorine is a pale yellow gas with a sharp, characteristic odor reminiscent of chlorine and ozone, detectable even with traces of fluorine. In liquid form, fluorine is canary yellow in color. The fluorine molecule is diatomic (F2); the heat of its dissociation is not precisely determined and, depending on the measurement method, ranges from 51 to 73 kcal/mol.
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Chemical properties of fluorine Fluorine in its compounds is only negatively monovalent. Already in the cold, fluorine is energetic: it combines with bromine, iodine, sulfur, phosphorus, silicon, and most metals, and these reactions are often accompanied by an explosion. The simplest means of extinguishing fires - water - burns in fluorine with a light brown flame. Fluorine forms organofluorine compounds with organic substances.
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Poisoning with fluorine and its compounds Acute fluorine poisoning in industrial conditions is observed extremely rarely, only in accidents. At high concentrations of hydrogen fluoride in the air, irritation of the eyes and mucous membrane of the larynx and bronchi, lacrimation, salivation, and nosebleeds occur. Hydrofluoric acid has a cauterizing effect on the skin, causing the formation of difficult-to-heal ulcers. Fluoride compounds inhibit the enzymes enolase, cholinesterase and others, and also cause disturbances in calcium and phosphorus metabolism. Treatment for poisoning with fluoride compounds is to drink a 0.5 - 1% solution of calcium chloride with a mixture of burnt magnesia, lavage the stomach with the same mixture; intravenous administration of 10% calcium chloride solution (10 ml).
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Safety precautions For individual protection from fluoride compounds, rubber gloves and shoes, special clothing, gas masks, dust respirators, etc. are used. Workers engaged in the production of fluorine, hydrofluoric acid, organofluorine compounds, in the production and use of beryllium fluoride and beryllium fluoroxide are subject to periodic medical examination once every 6 months, and in some industries – once a year. Additional special nutrition is prescribed for the production of superphosphate, cryolite, fluorine derivatives and fluorine-containing salts. B vitamins, calcium ascorbate, and foods rich in calcium are recommended.
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Applications The most widely used compounds are fluorides: oxygen fluoride is used in jet technology as the most powerful oxidizing agent after ozone, hydrofluoric acid is used as a solvent and for etching glass, boron fluoride is used in liquid form as an oxidizer of liquid jet fuel, for the fluorination of uranium compounds in the nuclear industry etc., uranium hexafluoride - for isolating the radioactive isotope of uranium in nuclear technology
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Applications: sulfur hexafluoride - as a gas for insulating high-voltage installations, sodium fluoride - to control agricultural pests, cryolite - in the production of aluminum, fluorspar is widely used in metallurgy and in the manufacture of enamels, elemental fluorine is used in liquid form as an oxidizer for jet fuel and To disinfect drinking water, freons are used as refrigerants in refrigeration units.
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Fluorine in the body Fluorine is a constant component of plant and animal organisms. When fluoride levels in water increase or decrease, illnesses occur in freshwater and terrestrial animals; for example, when the fluorine content in water is more than 0.00005%, fluorosis can develop - a disease accompanied by spotting of enamel and brittle teeth. When the fluoride content does not reach this level, dental caries occurs (destruction of tooth enamel and dentin). Fluorine enters a living organism, in addition to drinking water, with food products, which contain on average about 0.02-0.05 mg% fluoride.
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Conclusion As a result of my work on the topic of the abstract, I became acquainted with the properties of fluorine and its compounds in the process of studying various literature. The variety of inorganic and organic fluorine compounds and the wide range of their applications in everyday life was a revelation to me. Of course, it is a pity that my work is limited to purely theoretical content, but I hope that these materials will be of interest to other children who will study chemistry.