第十天化学知识点之推断实际应用部分（Tenth days of chemical knowledge, inference, practical application）

第十天化学知识点之推断实际应用部分（Tenth days of chemical knowledge, inference, practical application）Tenth daysThe inference and practical application of substances in chemical experimentsI. inferenceThe difficulty of the deduction question has been reduced now, and the condition given by the topic is very comprehensive. Just think it over a little. Then, when thinking about the question, try to think of junior high school, the answer often occurs in the matter, do not use what silver nitrate, such tests do not make the material required to speculate! A lot of practice, will be found in senior high school entrance examination answers the material that is generally in the H2 O2 Fe Cu Zn C CO CO2 CuO H2O Fe3O4 Fe2O3 H2O2 H2SO4 HCl Ca (OH) 2 NaOH CuSO4 FeSO4 CaCO3 Na2CO3.example1. cases of a compound 1.6g, complete combustion in the air after the formation of 4.4gCO2 and 3.6g on the composition of water, the compound has the following inference: must contain C and H; 2 must be free of O; and O; there must be O; the number of atoms in the molecule of C, H is 1:2; the molecular C, H atomic ratio is 1:4. which is correct (fill number) _.Answer: the 6 analysis: according to the conservation of elements, according to the content of carbon dioxide can be calculated in 1.2g, water content of hydrogen is 0.4g, so as to the quality of compound is 1.6g, so the material does not contain oxygen; then transformed according to the quality, can quickly get the H atom ratio is 1:4Examples of 2.A, B, C, and D are common substances in junior high schools. The relationships between each other are shown in the diagram. - - indicates the reaction between the two substances,- means the transformation between two substances, partial reactants or products, and the reaction conditions have been omitted).(1) if A is a gas element, D is a greenhouse gas.The chemical formula of A is _;The chemical formula D is _ B.(2) if A is a base, B is widely used in the production of glass, paper, textile and detergent.The chemical formula of C is _; B D is the chemical formula for _.(3) if A is an acid. The following statement is correct, _ (in number).B and D may all be elemental. B and C may be saltsA and D may also react. D must not be transformed into Canswer:(1) O2, II, 2CO, +O2, 2CO2(2) CO2 Na2CO3 + 2HCl = 2NaCl + H2O + CO2 =(3) one (2), 1 missing, 0 wronganalytic:(1) the first question is relatively simple, D must be CO2, A is a gas element, according to the block diagram relationship, it is easy to introduce A is oxygen;(2) B must be Na2CO3, which is widely used in the production of glass, paper, textile and detergent, only Na2CO3,So, the back is simple, A this base is certainly Ca (OH) 2, C can be NaOH, D is H2O;(3) A is acid, then the simplest, we can speculate that he is hydrochloric acid, B can be Fe, C can be Zn, D can be Cu; B can be CaCO3, C can be Na2CO3,D can be CO2; B can be Na2CO3, C can be Ca (OH) 2, D can be CaCO3, reference D. substance, we can see that D can be translated into ATwo, chemistry and practical application(1) environment and chemistryEnvironmental pollution mainly includes air pollution, water pollution, soil pollution, food pollution and so on. In addition, solid waste, radioactive and noise pollution are also included.1, air pollution and PreventionThe three major environmental problems in the world - acid rain, ozone depletion and greenhouse effects - are caused by air pollution. Sulfur oxides are mainly sulfur dioxide and sulfur dioxide three, most of which come from coal, non-ferrous metals smelting plants and sulfuric acid plants also emit a considerable amount of sulfur oxides. Carbon monoxide is mainly the product of incomplete combustion of fuels such as gasoline. Nitrogen oxides, mainly nitrogen oxides and nitrogen dioxide, contribute mostly to air pollution, mostly from fuel combustion, including emissions from automobiles. Chlorofluorocarbons from refrigerant freon, its main effect is the destruction of the ozone layer in the atmosphere.Acid rain contains a variety of inorganic acids and organic acids, most of which are sulfuric acid and nitric acid, usually sulfuric acid. It does great harm to living things, soil, buildings and so on. Easily lead to biological death, soil acidification, building corrosion.The extensive use of Freon is the main reason for the destruction of the ozone layer, the ozone layer depletion, ultraviolet radiation absorption ability will be greatly reduced, skin cancer increased; in addition the UV will damage the cornea and lens, cataract, crystal deformation caused by ultraviolet enhancement,It can cause a large number of deaths in shrimp, crab larvae and shellfish, as well as weaken photosynthesis and impede the normal growth of crops and trees.The greenhouse effect causes the average temperature of the earth surface to rise, mainly because of the great increase in carbon dioxide content. When it is serious, it will destroy the ecological balance, increase sea levels, increase precipitation, and form floods. It is necessary to change the fuel structure, develop solar energy, nuclear power instead of fossil fuels, increase ground greening, and effectively enhance photosynthesis.2, water pollution and controlWater pollution usually refers to the deterioration of water quality caused by human factors and reduces the value of water use. The phenomenon of eutrophication in rivers and lakes is called algal bloom, which is called red tide in coastal areas. In areas where red tides or blooms occur, some plankton reproduce rapidly and turn water into red. Hence, they are called red tides. These algae are foul smelling, poisonous, and fish are inedible. Algae shield the sun and cause underwater organisms to die because of photosynthesis. These dead creatures decay and release nutrients such as nitrogen and phosphorus, which are then used by algae. In this way, the older month brings about a vicious circle.The prevention and control of water pollution, mainly to solve the problem of pollution sources, and is a comprehensive management in the industrial production of waste, waste water, waste gas and waste residue comprehensive utilization; two, the city sewage concentrated treatment, can not discharge. Three, it is necessary to use pesticides and fertilizers reasonably in agricultural production.(two) energy and chemistry1, conventional energy - fossil fuelsConventional energy sources are mainly fossil fuels such as coal, oil and natural gas.Coal plays an important role in the national economy. It is called black gold and food of modern industry. It is a complex mixture of organic and inorganic substances, mainly containing C elements. The main way to process coal is to insulate it from the heat of the air and decompose it into coke, coal tar and coke oven gas. Coke is an important raw material for metallurgical industry, coal tar is an important chemical raw material, and coke oven gas is an important fuel. In the process of processing coal and using coal as fuel, the coal ash, cinder, waste gas and waste liquid should be properly treated and utilized, and the pollution and environmental protection must be eliminated. Oil is called the blood of modern industry and is also a mixture of two elements, carbon, hydrogen, and a small amount of elements such as S, O, N and so on. Because of its complex composition, it is rarely used directly. It is generally refined. By refining, fuels such as gasoline, kerosene, diesel oil, lubricating oils for various machines and many gaseous hydrocarbons can be obtained by refining. In the process of the development of the petroleum industry, we must attach great importance to the petroleum refining, petrochemical and other industrial waste, waste and waste and undersea oil tanker transportation, on the ground and air, rivers and lakes pollution. Natural gas is the most important gas mineral fuel in the world today. The main component is methane. It is an important energy source in the underground. It is also a relatively small fuel for pollution.2, green energy - solar energySolar energy is a huge energy source that can be used by humans through four channels: (1) through the ascending cycle of the atmosphere and water,Wind, flowing water, waves, currents, etc., are presented in the form of wind, water, and water. (2) absorbed by the ocean, become the internal energy of the ocean, and then release it in the form of tidal energy. (3) convert and store solar energy through the photosynthesis of plants, and then release it in the form of vegetation, methane, coal, oil, natural gas and other fuels. (4) by converting electricity into direct use, such as solar cameras, solar telephones, solar refrigerators, solar TV sets, solar homes.3, other energy - hydrogen energy, nuclear energyAs a new type of energy, hydrogen is attracting more and more attention. The main advantages are as follows: (1) mineral resources are limited, and hydrogen can be produced by using water as raw material. It has a wide range of sources. (2) when hydrogen burns, it emits more heat, and the heat per kilogram of hydrogen burns up to 143 million Jiao, which is three times as much as that of the same quality gasoline. (3) the product of hydrogen combustion is water, no pollution to the environment. It is a clean energy source. The development of hydrogen energy also needs to solve such problems as how to prepare hydrogen cheaply and extensively and how to safely store and transport hydrogen gas.Nuclear energy is a symbol of the advanced progress of modern human society and a clean energy source. The main advantages are as follows: (1) clean and relatively safe. (2) nuclear fuel is rich in resources. Deuterium in the Sea reserves of 45 trillion tons, as energy resources, can be used for tens of billions of years of mankind. (3) a small amount of nuclear fuel can ease the tension in transportation. (4) low cost and cost-effective. The worlds first nuclear power plant was built in the former Soviet Union in Austria, Bunin, and it was put into operation in June 27, 1954,Its thermal power is 30 thousand kw. The first Qinshan nuclear power station designed and built in China in December 15, 1991, generating power of 300 thousand kilowatts.(three) life and chemistry1 food and chemistryHuman food contains six major nutrients: vitamins, inorganic salts, and water. From the composition of food chemistry, food nutrition is the most content of carbohydrate, fat, protein, the nutritional composition of three kinds of nutrition is the most direct, and can produce heat, the nutrition is referred to as the three major nutrients.2, trace elements and human healthThere are 25 kinds of essential elements in human body, which can be divided into constant and trace elements according to their content95%, there are 11 kinds: C, H, O, N, P, S, Na, K, Ca, Mg, C1, and a. Essential trace elements have 14 kinds: Fe, Zn, Cu, Mn, B, Mo, Co, Se, A1, V, Ce, F, I, Si, trace elements on human health has a very important role, such as:Zinc: mainly in the eyes, hair, liver, kidney, blood, skin. Zinc deficiency, slow growth, delayed sexual maturation, changes in taste and olfaction. When the ratio of copper to copper is imbalance, it is easy to suffer from coronary heart disease and cause myocardial infarction.Iodine exists mainly in the human thyroid, iodine deficiency can cause mental retardation. Consumption of iodized salt, mainly KIO3, eat iodine rich foods can prevent some diseases.Iron: mainly in the hemoglobin of red blood cells in the human body, iron deficiency can cause anemia in humans. Selenium acts as an enzyme in the human body and strengthens some other enzymes,Can eliminate metabolic waste and other harmful substances, the lack of selenium can lead to resistance to decline in the body, susceptible to a variety of chronic diseases. Fluorine can protect teeth and prevent dental caries.Molybdenum: one of the seven essential trace elements of the brain. It has the function of nitrogen fixation. It is an anti-cancer element. Many cancers, such as esophageal, liver, rectum and breast cancer, are related to molybdenum deficiency.3. Important chemicals in the human bodyHydrochloric acid: in gastric juice, what people call gastric acid, its component basically is hydrochloric acid, the range of pH inside human stomach normally is 1.23.0. Its role is to activate pepsin, which converts it into active pepsin and provides a suitable acidic environment. But gastric acid is overmuch, to gastric and duodenum mucous membrane has erosion action, can take sodium bicarbonate or aluminium hydroxide medicaments.(four) materials and chemistry1, clothing fiberA fiber is a linear polymer material that has or is able to maintain a length of 100 times greater than its own diameter. Can be divided into two kinds of natural fiber and chemical fiber, natural fiber can be divided into animal fibers (such as wool, silk) and plant fiber (such as cotton, hemp, etc.); chemical fiber can be divided into artificial fiber (fiber regeneration of natural plant fiber by chemical treatment) and synthetic fibers (such as nylon, polyester acrylic, polypropylene, etc.).2 、 new inorganic non-metallic materialsHigh temperature structural ceramics, such as alumina ceramics and silicon nitride ceramics, have the characteristics of high temperature resistance, no oxidation, acid and alkali corrosion resistance, high strength and small density.Utilize renewable resources.The green chemical reaction, a chemical reaction with atom economy as the basic principle in the chemical reaction to obtain new material, make full use of every raw material in the reaction of atom, to achieve zero emissions; the reaction process does not produce other products; reaction using nontoxic and harmless solvent, additives and catalysts.The green products, the production of non-toxic, environmentally friendly products to protect the environment and human security.In addition, green chemistry is commonly referred to as the waste water, waste and other environmental pollution control technology of local terminal, but eliminated from the source pollution, a new concept that no longer produce waste. Green chemistry is the chemistry that completely eliminates pollution. It is the goal of chemical research and chemical industry production technology development in twenty-first Century.White pollution as a proper term for the environment, refers to polyethylene and other plastic waste, such as disposable snack boxes, plastic convenience bags, agricultural films, etc., they are difficult to degrade.The acid rain is normal, the rainwater is acidic, and the pH is about 67. This is because CO2 in the atmosphere dissolves in the rain water and forms partially ionized carbonic acid: CO2 (g) + H2O, H2CO3, H+ + HCO3-Rainwater is weak acid, can make the soil nutrient dissolved, for biological absorption, this is conducive to human environment. Acid rain usually refers to precipitation of less than 5.6 pH, which is one of the phenomena of air pollution.The NO produced in the combustion process combines with O2 in the air as NO2, and NO2 in water produces nitric acid.The reaction process can be expressed as: 2NO = 2NO2 + O2 + H2O = 2HNO3 + NO 3NO2Acid rain can make rivers and lakes sprinkling water acidification, poison fish and other aquatic organisms; soil acidification, destroying farmland, damage to crops and forests; acid rain also corrosion of buildings, metal products, and other places of historic interest and scenic beauty.Greenhouse effect the increase of carbon dioxide in the atmosphere is mainly caused by burning large amounts of fossil fuels. In addition, deforestation, green area reduction is also an important reason. The greenhouse effect will reduce the sea ice, increase sea level, increase precipitation, and adapt to a change in the biological growth environment that has been adapted for a long time, and destroy the ecological balance. To make the earths surface temperature remained normal, not increased significantly, we must proceed from changing the fuel structure, the development of solar energy, nuclear energy to replace fossil fuels, increase the surface of the green area, effectively increase the photosynthesis.Ahmed Xavier, a prize winner of the Nobel prize in Chemistry for 2 and 1999, created a new field of femtosecond chemistry, making it possible to observe the motions of atoms in molecules that use laser spectroscopy to observe chemical reactions. What you dont think the technology can observe is ()A. the decomposition of reactant molecules in chemical reactions; the motion of atoms in B. reactionsC. the formation of molecules in a chemical change; the internal composition of the D. nucleusanswer DIt is possible to observe the motion of atoms in molecules in chemical reactions by laser spectroscopy, which means that the internal composition of nuclei smaller than atoms cannot be observed.Femtosecond chemistry refers to the use of laser spectroscopy to observe the transition state of chemical reactions. The actual time measurement of the femtosecond chemical reaction, 1 femtosecond = 10-15 seconds. Take a femtosecond for 1 seconds, then one second is equivalent to thirty-two million years. Ahmed Xavier using femtosecond spectroscopy can be described as the worlds fastest camera, because of his laser flash time is so short that can measure femtosecond, with spectral technology, people can look like a slow motion is a kind of chemical reaction is observed in reaction process, the atomic motion is no longer just imagine or, that the calculation results, we can clearly see the image of a single atomic motion and the transition state of molecules . Activation, barrier, transition state and so on, are no longer some vague words.Example 3. In recent years, many cities in China have banned the use of leaded gasoline, mainly due to ()A. improves gasoline combustion efficiency by B. and reduces gasoline costC. avoids lead pollution in the atmosphere; D. lead resources are in short supplyanswer CExample 4. hydrogen will be a promising new energy source. The best way to produce hydrogen by water as raw material isA, from the power station to provide power to improve the electrolysis of water B, coke and gas water production methodC uses solar energy to break down water D and to make the red hot iron react with water to form hydrogen gasanswer CExample 5. The new material, nano alpha -Fe, has super magnetic properties,Medium for high density magnetic recording, and efficient catalysts. Laboratories use gas nano alpha -Fe by phase reduction method is: solid powder FeCl2 nH2O dehydration, vacuum drying, and then pass into the high purity nitrogen under high temperature conditions (as protective agent) and hydrogen (reductant) mixed gas, generating nano alpha -Fe. Please answer the following questions:(1) write out the chemical equation for producing nano alpha -Fe:(2) the role of high purity nitrogen gas as protective agent in the reaction is that:answer(1) H2 + FeCl2, Fe + 2HCl(2) prevent the formation of nano alpha -Fe to be oxidizedanalysis nano materials, like grain, are always the material basis for human survival and development. Most of the material is solid, and its particle size is generally in the micrometer scale. A particle contains numerous atoms and molecules, at this time, the material shows the macroscopic properties of a large number of molecules. If a special method is used to process the particles to na