Chemistry is a science that studies the composition, structure, properties and changing laws of matter.
First, the principle of drug accessibility.
1, the use of drugs should be "three noes": don't touch drugs directly with your hands, don't put your nostrils close to the mouth of the container to smell the smell of drugs, and don't taste any drugs.
2. Pay attention to economy when taking medicine: take medicine in strict accordance with the dosage prescribed by the laboratory. If the dose is not specified, the minimum amount is usually taken, that is, 1-2mL of liquid, and the bottom of the test tube is covered with solids.
3. The leftover drugs should be "three noes": that is, don't put them back in the original bottle, don't throw them away at will, don't take them out of the laboratory, and put them in the designated container.
4. If the liquid medicine spills into your eyes during the experiment, wash it with water immediately. Second, obtain solid drugs.
1, blocky or dense solid particles are generally taken with tweezers.
2. Keys (or paper slots) for powdered or granular drugs.
3. Used tweezers or keys should be wiped with clean paper immediately.
Second, get the liquid medicine (stored in a narrow bottle)
1, contact with a small amount of liquid medicine-use a rubber pointed dropper.
The dropper containing liquid medicine should be hung vertically above the instrument. Drop the liquid medicine into the instrument receiving the liquid medicine, and do not let the dropper containing the liquid medicine touch the instrument wall. Do not put the dropper flat on the test bench or other places to avoid polluting the dropper; Do not suck other reagents with unwashed droppers (the droppers on the dropper bottle are not interchangeable and do not need to be cleaned).
2. When taking the test solution from the narrow bottle, remove the cork and put it on the table; When pouring liquid, make the label face the palm of your hand, and the bottle mouth is close to the test tube mouth or instrument mouth to prevent the residual liquid medicine in the bottle mouth from flowing down and corroding the label.
3, the use of measuring cylinder
A, take a certain volume of liquid medicine and measure it with a measuring cylinder.
When reading, the measuring cylinder must be placed smoothly, and the line of sight should be flush with the lowest concave liquid level in the measuring cylinder. The top reading is high and the bottom reading is low.
B, measuring the volume of liquid: firstly, pour the liquid into the measuring cylinder until it approaches the required scale, and then drop it to the scale line with a dropper.
Note: The measuring cylinder is a measuring instrument, which can only be used to measure liquids, and cannot store drugs for a long time, nor can it be used as a container for reaction. It cannot be used to measure supercooled or overheated liquids, nor should it be heated.
C, reading, if you look up, reading is lower than the actual volume; Looking down, the reading is higher than the actual volume.
Third, the use of alcohol lamps.
1, alcohol lamp flame: divided into three layers: external flame, internal flame and flame core.
The outer flame temperature is the highest and the inner flame temperature is the lowest. When heating, the heating substance should be placed in the outer flame part.
2. Precautions for the use of alcohol lamps: a. The alcohol in alcohol lamps shall not exceed 2/3 of the volume; B, the alcohol lamp must be covered with a lamp cap after use, and cannot be blown out by mouth; C it is absolutely forbidden to add alcohol to the burning alcohol lamp; D it is absolutely forbidden to light another alcohol lamp with a burning alcohol lamp, so as not to cause a fire. E, when not using alcohol lamp, cover the lamp holder to prevent alcohol volatilization.
3. Instruments that can be directly heated are: test tubes, evaporating dishes, burning spoons, crucibles, etc. The instruments that can be heated but must be covered with asbestos mesh are beakers and flasks; Instruments that cannot be heated are: measuring cylinder, glass rod and gas container.
4. When heating the medicine, first dry the instrument, preheat it, and then heat it under the medicine; When heating solid medicine, the medicine should be placed flat, and the mouth of the test tube should be slightly inclined downward to prevent water from flowing back into the test tube and breaking the test tube; When heating the liquid medicine, the volume of the liquid shall not exceed 1/3 of the volume of the test tube, and the test tube shall be tilted upward by 45, and the mouth of the test tube shall not face itself or others. Fourth, clean the instrument:
1, brush with a pipe brush. When scrubbing, the tube brush must be rotated or moved up and down, but the force should not be too great to prevent damage to the test tube.
2. The sign of the cleanliness of the instrument is that the water attached to the inner wall of the glass instrument has neither gathered into water droplets nor flowed down in strands.
Fourth, activity exploration.
1, candle and its burning: P7-P9
2. Discuss the air inhaled and the gas exhaled by human body: p10-p12.
Six, the characteristics of green chemistry: P6
Unit 2: The air around us
I. Basic concepts
1. Physical change: no change of new substances. Such as the melting of paraffin, the evaporation of water
2. Chemical changes: changes in the formation of new substances. Such as the burning of matter and the rusting of steel.
Basic characteristics of chemical change: the first generation I. Basic concepts
New substance. Chemical changes must be accompanied by physical changes, and physical changes are not accompanied by chemical changes.
3. Physical properties: the properties displayed without chemical changes. Such as color, state, smell, density, solubility, volatility, hardness, melting point, boiling point, electrical conductivity, thermal conductivity, ductility, etc.
4. Chemical properties: the properties of substances in chemical changes (flammability, combustion-supporting, oxidation, reducibility and stability). For example, iron rusts easily, and oxygen can support combustion.
5. Pure substance: consisting of only one substance. Such as N2 O2 CO2 P2O5, etc.
6. Mixture: It is made by mixing two or more substances. Such as air, sucrose water, etc. (The ingredients in it keep their original properties)
7. Simple substance: pure substance composed of the same elements. Such as N2 O2 S P, etc.
8. Compound: a pure substance composed of different elements. Such as CO2 KClO3 SO2, etc.
9. Oxide: A compound of oxygen, one of the two elements in a pure substance. Such as CO2 SO2, etc.
10. Combination reaction: a reaction in which two or more substances form another substance. A+B ==AB
1 1. decomposition reaction: a reaction in which one reactant generates two or more other substances. AB ===A +B
12, oxidation reaction: the reaction between substances and oxygen. (Slow oxidation is also an oxidation reaction)
13. catalyst: a substance that can change the chemical reaction rate of other substances in a chemical reaction, but its own quality and chemical properties have not changed before and after the reaction. (also called catalyst) [It should be said that a substance is a catalyst for a certain reaction, and if manganese dioxide is not a catalyst, it should be said that manganese dioxide is a catalyst for the decomposition reaction of potassium chlorate]
14, catalysis: the role of catalysts in the reaction.
Second, the composition of the air.
1, Determination of oxygen content in air —— Combustion experiment of excessive red phosphorus P23
Question: (1) Why does red phosphorus exceed the standard? (Oxygen depletion)
(2) Can red phosphorus be replaced by sulfur, charcoal, iron wire and other substances? (can't, produce new substances)
2. Composition of air:
N2: 78% O2: 2 1% Rare gas: 0.94% CO2:0.03%%% Other gases and impurities: 0.03%.
3. Use of oxygen: for breathing and supporting combustion.
4. Use of nitrogen: P24
5. Properties and uses of rare gases: P25
6. Air pollution: (Daily air quality report and forecast)
(1) Pollution source: mainly the combustion of fossil fuels (coal, oil, etc.). ), factory exhaust gas, automobile exhaust gas, etc.
(2) Pollutants: mainly dust and gas. Such as SO2, CO and nitrogen oxides.
Third, the nature of oxygen.
1, physical properties of oxygen: colorless and odorless gas, slightly higher in density than air, and insoluble in water. It can be liquefied into light blue liquid or solidified into light blue solid under certain conditions.
2. Chemical properties of oxygen: It is a common oxidant with active chemical properties and strong oxidation.
(1) can help combustion: check with the wooden strips with Mars, and the wooden strips will re-ignite.
(2) the reaction of oxygen with some substances:
The conditions of the reaction of active substances with oxygen and the name of the phenomenon product of oxygen reaction and the expression of chemical formula and chemical reaction.
Sulfur S+O2 ==SO2 (in air-light blue flame; Violet-blue flame in oxygen)
Aluminum foil 4Al+3O2 ==2Al2O3
C+O2==CO2
Iron 3Fe+2O2 == Fe3O4 (intense combustion, sparks everywhere, releasing a lot of heat and producing black solids).
Phosphorus 4P+5O2 == 2P2O5 (white smoke and white solid P2O5 are produced).
Fourth, the laboratory preparation of oxygen
1, drugs: hydrogen peroxide and manganese dioxide or potassium permanganate or potassium chlorate and manganese dioxide.
2, the reaction principle:
(1) hydrogen peroxide+oxygen
(2) potassium permanganate+manganese dioxide+oxygen (a mass of cotton at the mouth of the catheter)
(3) Potassium chlorate, potassium chloride and oxygen
3. Experimental devices P34 and P35
4. Collection method: the density is higher than air-upward exhaust method (the duct mouth should extend to the bottom of the gas container to drive out the air in the gas container).
Insoluble in water or insoluble in water, it does not react with the drainage method (when there are bubbles at first, because there is air in the container or conduit, it cannot be collected immediately, only when the bubbles escape continuously and evenly; When bubbles appear at the edge of the gas container, it means that the gas has been collected completely). The gas collected in this way is relatively pure.
5, operation steps:
Inspection: Check the air tightness of the equipment. Such as P37
Filling: put the medicine into the test tube and plug the test tube with a single-hole rubber stopper with a catheter.
Fixing: Fix the test tube on the iron frame.
Key points: ignite the alcohol lamp, first heat the test tube evenly and then heat it to the drug part in the test tube.
Collection: collect oxygen by drainage.
Separation: after collection, first pull the catheter out of the sink.
Extinguish: Extinguish the alcohol lamp.
6. Inspection method: Insert the wooden stick with Mars into the gas container. If the stick is rekindled, the gas in the bottle is oxygen.
7, full inspection method:
(1) When collecting by the upward exhaust method: put the wooden strip with sparks on the bottle mouth. If the wood is rekindled, it means that the oxygen in the bottle is full.
(2) Drainage and collection: When bubbles appear at the edge of the gas container, it means that the oxygen in the bottle is full.
8. Notes:
(1) The mouth of the test tube should be slightly inclined downward (when the solid drug is heated) to prevent the water in the drug from becoming steam after being heated, and then condensing into water drops, which will flow back to the bottom of the test tube and cause the test tube to break.
(2) Don't extend the catheter into the test tube for too long, just slightly expose the rubber plug to facilitate the exhaust.
(3) The drugs in the test tube should be laid flat at the bottom of the test tube and heated evenly.
(4) The iron clip should be clamped in the middle and upper part of the test tube (about 1/3 from the test tube mouth).
(5) aiming the external flame of the alcohol lamp at the drug part for heating; When heating, first move the alcohol lamp down the test tube to make the test tube heated evenly, and then heat it at the drug site.
(6) When collecting gas by drainage method, the gas collector is filled with water and then poured into the water tank (the bottle mouth should be below the water surface), and the conduit can extend to the bottle mouth; When collecting by upward exhaust method, the gas cylinder should be placed directly, and the conduit mouth should be close to the bottom of the gas cylinder.
(7) When gas is collected by drainage method, attention should be paid to the collection when bubbles are continuously and uniformly released from the conduit mouth, otherwise the collected gas will be mixed with air. When a bubble comes out of the gas container, it proves that it is full.
(8) When stopping the reaction, unplug the catheter first, and then move the alcohol lamp (to prevent the water in the sink from flowing back into the test tube and causing the embassy to break).
(9) The container containing oxygen should be placed upright, and the bottle mouth should be covered with glass.
(10) When making oxygen with potassium permanganate, a small cotton ball is held at the mouth of the test tube.
Five, industrial oxygen production method-liquid air separation method.
Low temperature and pressure make air become liquid air and then evaporate. Because the boiling point of liquid nitrogen is lower than that of liquid oxygen, nitrogen first evaporates from liquid air, and the rest is mainly liquid nitrogen.
Unit 3: Water in Nature
I. Composition of water
1. Electrolyzed water experiment: Electrolyzed water reacts chemically under the action of direct current. Water molecules are decomposed into hydrogen atoms and oxygen atoms, which form hydrogen molecules and oxygen molecules in pairs, and many hydrogen molecules and oxygen molecules gather into hydrogen and oxygen.
2, one positive oxygen, two negative hydrogen
Expression of experimental phenomena
There are bubbles on the electrolytic water test electrode, and the volume ratio of anode and cathode gas is 1: 2. Negative qi can be burned, and positive qi can be rekindled with mars. Water, oxygen and hydrogen (decomposition reaction)
2H2O energized 2H2 =+O2 =
3. Composition of water: Water is pure and a compound. Macroscopically, water is composed of hydrogen and oxygen, and water is a compound. Microscopically, water is composed of water molecules, which are composed of hydrogen atoms and oxygen atoms.
4, the nature of water
(1) Physical properties: colorless, odorless and tasteless liquid, with boiling point of 100℃, freezing point of 0℃ and density of 1g/cm3, which can dissolve various substances to form solutions.
(2) Chemical properties: Water can be decomposed into hydrogen and oxygen when charged, and it can also react with many simple substances (metals, nonmetals), oxides (metal oxides, nonmetallic oxides), salts and other substances.
Second, hydrogen.
1, physical properties: colorless and odorless gas, insoluble in water, less dense than air, the lowest density gas under the same conditions.
2. Chemical characteristics-flammability.
When burning in air (or oxygen), a lot of heat is released, the flame is light blue, and the only product is water.
Note: The mixed gas of hydrogen and air (or oxygen) may explode when exposed to an open flame, so it must be pure before igniting hydrogen. (Purity test method: collect hydrogen in the test tube, block the test tube mouth with your thumb, move the test tube mouth down to the flame of alcohol lamp, loosen your thumb and light it. If the sharp sonic boom shows that hydrogen is impure, it needs to be collected again and tested again; A low voice means that hydrogen is pure. )
Third, molecules.
1, definition: molecules are the smallest particles that keep the chemical properties of substances.
2, the characteristics of the molecule:
(1) molecule is very small, with small mass and volume.
(2) Molecules are always in motion. The higher the temperature, the greater the energy and the faster the movement speed of molecules.
(3) There are forces and spaces between molecules. The total volume of different liquids after mixing is usually not equal to the simple addition of several liquid volumes, because there is a certain force and space between molecules. (Thermal expansion and cold contraction)
3. Explain these phenomena in daily life:
A: I passed by the winery and didn't drink, but I could smell the wine?
B: I work in a cigarette factory. I can't smoke, but I smell like smoke?
C: Wash the wet clothes and dry them. So, where did the water go?
D: Sugar will gradually disappear when you put it in water, but the water is sweet. Why?
E: Half a glass of alcohol is poured into half a glass of water, but less than one glass. What happened?
Four. atom
1, definition: atom is the smallest particle in chemical change.
2. The essence of chemical change: molecular differentiation and atomic recombination.
3. Comparison between molecules and atoms:
Atomic and molecular annotation
The smallest particles in conceptual chemical changes keep the chemical properties of substances. Are atoms necessarily smaller than molecules?
The similarity is small, light and spaced.
Atoms of the same kind have the same properties;
Different kinds of atoms have different properties; Small, light and spaced. Homologous molecules have the same properties;
Different kinds of molecules have different properties;
In chemical reactions, heterogeneity is inseparable. In chemical reactions, it splits into atoms, which combine to form new molecules.
Interrelated atoms can form molecules, and molecules form substances. For example, atoms such as oxygen and nitrogen can also directly form substances. Metal molecules are made up of atoms.
Countless molecules of the same kind make up matter. How many kinds of particles does matter consist of?
Verb (abbreviation for verb) Classification, composition and composition of matter
Matter is composed of elements.
2. The particles that make up matter are molecules, atoms and ions.
3, the classification of substances, pure substance compound mixture
Immutable verb water purification
1, purify water (1), add flocculant to absorb impurities (adsorption precipitation) (2), filter (3), and disinfect (add chlorine or chlorine monoxide).
2. Water purification function of activated carbon: it has a porous structure and has a strong adsorption capacity for gas, steam or colloidal solids. It can adsorb pigment to make the liquid colorless and remove odor.
3. Hard water and soft water
(1) Difference: How many soluble calcium and magnesium compounds are contained in water.
(2) Softening method of hard water: boiling or distillation
Seven, the classification method of substances
1, filtration: separating the mixture of soluble and insoluble substances (note: "one paste", "two low" and "three dilute")
2. Distillation: separating mixtures of substances with different boiling points.
Eight, care for water resources
1, human-owned water resources P57—P59
2. Water resources and water pollution in China: The main sources of water pollution are industrial pollution, agricultural pollution and domestic pollution.
3. Caring for water resources-a sign of saving water.
(1) Save water and improve water utilization. Save water, on the one hand, to prevent waste of water; On the other hand, it is necessary to reduce a large amount of industrial, agricultural and domestic water and improve water utilization by using new technologies, reforming processes and changing habits.
(2) Measures to prevent and control water pollution: A, reduce the generation of pollutants B, treat the polluted water to meet the discharge standard C, advocate the use of farm manure in agriculture, rationally use chemical fertilizers and pesticides D, and discharge domestic sewage after centralized treatment.
Unit 4 The Mystery of Material Composition
A, the composition of the atom:
Proton: 1 proton with 1 unit positive charge.
Nucleus (+)
Neutron: uncharged
atom
An uncharged electron (1) has 1 electrons and a negative charge of 1 unit.
1. There are three kinds of particles that make up atoms: protons, neutrons and electrons. But not all atoms are made up of these three particles. If there is a hydrogen atom with only protons and electrons, there is no neutron.
2. In an atom, the number of positive charges (nuclear charges) carried by the nucleus is the number of charges carried by protons (neutrons are uncharged), and each proton band 1 unit positive charge, so the number of nuclear charges = the number of protons, and the number of masses in the nucleus is equal to the number of electrons outside the nucleus, so the number of nuclear charges in the nucleus = the number of protons = the number of electrons outside the nucleus.
There are charged particles in the atom. Why doesn't the whole atom show electricity?
Atoms are composed of positively charged nuclei and electrons with negative charges outside the nuclei. Nuclei are composed of protons and neutrons. Protons are positively charged and neutrons are uncharged. The positive charge (nuclear charge number) of the nucleus is equal to the negative charge of the electrons outside the nucleus, but the electrical property is opposite, so the whole atom is not electrical.
2. Relative atomic mass:-The international standard is112 of the mass of a carbon atom, and the ratio of the mass of other atoms to it is regarded as the relative atomic mass of this atom.
Relative atomic mass of element atom = actual mass of element atom/(actual mass of carbon atom ×112)
note:
1. The relative atomic mass is only a ratio, not the actual atomic mass. Its unit is 1, abbreviated.
2. In the calculation of relative atomic mass, the selected carbon atom is carbon 12, containing 6 protons and 6 neutrons, and its mass112 is approximately equal to 1.66× 10-27 kg.
Third, the elements:
1. Definition: The general term for a class of atoms with the same nuclear charge (i.e. the number of protons in the nucleus).
2. Element content in the crust: Si-Al-Fe.
The most nonmetallic element, the most metallic element.
3. Differences and connections between elements and atoms
Elemental atom
The concept of a class of atoms with the same nuclear charge. The smallest particle in chemical change.
Distinguish only about types, not quantity, and have no sense of quantity. In other words, there are kinds, numbers and quantities.
Scope of use should be used to describe the macroscopic composition of matter. Used to describe the microstructure of matter.
For example, water contains hydrogen and oxygen. Namely. Water consists of hydrogen and oxygen. Such as; A water molecule consists of two hydrogen atoms and one oxygen atom.
The smallest particle connecting elements.
Element = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = atom.
A general term for a class of atoms.
4. The meaning of the element symbol: a. Represents an element. The table is an atom of this element.
For example: the meaning of o: the meaning of n:
5. Writing of element symbols: Remember the symbols of common elements.
Metal element
6. Element classification
Non-metallic elements liquid solid gaseous rare gas elements
7. Periodic Table of Elements
Four. ion
1, the arrangement of extranuclear electrons-represented by the atomic structure diagram of elements
2. Understand the meaning of the atomic structure diagram-the atomic structure diagram of1-18 elements.
3. The relationship between the properties of elements and the outermost electron number.
A. Rare gas elements: the outermost layer has a stable structure with 8 electrons (2 helium) and its properties are stable.
B, metal elements: The number of electrons in the outermost layer is generally less than 4, and electrons are easily lost.
C. Non-metallic elements: Generally, the number of electrons in the outermost layer is greater than or equal to 4, and it is easy to obtain electrons.
4. Formation of ions: charged atoms formed after atoms gain or lose electrons.
Electrons of negatively charged atoms form anions.
Atoms lose electrons, are positively charged and form cations.
5. Expression of ions-ion symbols. The ion symbol represents the molecular formula Xn+ or Xn-, X represents the chemical formula of the element symbol or atomic group, the "+"or "-"in the upper right corner of X represents whether the ion is positively charged or negatively charged, and N represents the charge of n units. For example, Al3+ stands for 1 aluminum ion with 3 units of positive charge; 3SO42- means three sulfate ions with two negative charges.
Verb (abbreviation of verb) chemical formula
1. Definition: a formula for representing the composition of matter with element symbols.
2. Importance:
(1). stands for a substance;
(2). Represents the elements that make up this substance;
(3). Represents the atomic number ratio of various elements;
(4) molecules representing this substance (for substances composed of molecules).
For example, HO2 means that water is composed of hydrogen and oxygen;
Water is made up of water molecules;
Water molecules are composed of hydrogen atoms and oxygen atoms;
A water molecule consists of two hydrogen atoms and 1 oxygen atom.
Valence of intransitive verbs
1, o usually shows -2 valence, and hydrogen usually shows+1 valence; Metal elements usually show positive valence; The valence has changed.
2. Application of valence: The algebraic sum of valence of each element in the compound is 0.
3, pay attention to when writing chemical formula according to the positive and negative valence, according to Zuo Zheng right negative ammonia dedicated to write.
4. Remember the valence of common elements.
7. 1, the number before the element symbol: the number of atoms is 2N.
2. Number before chemical formula: indicates the number of molecules of 2H2O.
3. The number before the ion symbol: indicates the number of ions.
4. The number in the upper right corner of the element symbol indicates the charge number Mg2+ carried by the ion.
5. The number directly above the element symbol: indicates the valence of the element.
6. The number in the lower right corner of the element symbol in the chemical formula indicates the number of atoms of H2O contained in the molecule.
Eight. Relative molecular mass: the sum of the relative atomic masses of each atom in the chemical formula.
For example, the relative molecular weight of H2O =1× 2+16 =18co2 =12+16× 2 = 44.
The relative molecular weight of NaCl is 23+35.5 = 58.5; The relative molecular weight of KClO3 is 39+35.5+16× 3 =122.5.
According to the chemical formula, the mass ratio of each element in the compound can also be calculated.
For example, in H2O, the mass ratio of hydrogen to oxygen is1× 2:16 = 2:16 =1:8.
In CO2, the mass ratio of carbon to oxygen is12:16× 2 =12: 32 = 3: 8.
For example, the mass fraction of nitrogen in ammonium nitrate (NH4NO3) is calculated.
1 First calculate the relative molecular weight of ammonium nitrate =14+1× 4+14+16× 3 = 80.
2. Then calculate the mass fraction of nitrogen:
Unit 6: Carbon and Carbon Oxide
First of all, several simple carbon substances
1. diamond (good dispersibility, hard)
2. Graphite (soft and slippery. Conductive, high temperature resistant)
3.C60 (composed of molecules)
Attribute: 1. Inactive at room temperature.
2. Combustibility C+ O2== (ignition) CO2 2C+ O2== 2CO
3. Reducing C+2CuO==2Cu+ CO2
4. Amorphous carbon 1. Adsorption of charcoal and activated carbon
2. Coke steelmaking
3. Carbon black pigment
Second, the laboratory preparation of carbon dioxide
1. Physical properties: generally, it is a colorless and odorless gas with a slightly higher density than air and can be dissolved in water.
Chemical properties: generally speaking, it cannot burn, does not support burning, and cannot provide breathing.
Reaction of CO2 +H2O with water = = H2+ CO2
CO2+Ca(OH)2==CaCO3+ H2O reacts with limewater.
2. limestone (or marble) and dilute hydrochloric acid
3. The main component CaCO3+2HCl==CaCl2+H2O+CO2.
4. Experimental device: solid-liquid normal temperature.
Collection method: upward ventilation method.
5. Inspection: (Verification) Put the burning batten and clarified limewater (after inspection) in the bottle mouth.
6. Uses: fire fighting, gas fertilizer, chemical raw materials, artificial rainfall dry ice and refrigerant.
Third, the nature of the company.
1. Physical properties: generally colorless and odorless gas, slightly less dense than air, hardly soluble in water.
Chemical properties: combustible 2CO+ O2== 2CO2.
Reduced CO+CuO==Cu+ CO2
Toxicity: People are poisoned by lack of oxygen.
Unit 7 Fuel and Its Function
First of all, the conditions of combustion
1. combustible
2. Oxygen (or air)
3. Reach the minimum temperature required for combustion (also called ignition point).
Second, the principles and methods of fire fighting
1. Remove combustible materials or isolate combustible materials from other items.
Cut off oxygen and air
3. That is, the temperature drops to the ignition point.
Fossil fuels: coal, oil and natural gas.
Influence of fossil fuels on air: coal and gasoline combustion pollute the air.
Fourth, clean fuels: ethanol and natural gas.
Verb (abbreviation of verb) energy 1. Fossil energy. Hydrogen energy 3. Solar energy. nuclear power
The development and utilization of these energy sources can not only partially solve the problem of fossil energy depletion, but also reduce environmental pollution.
Unit 8: Metals and Metal Materials
A, metal activity sequence table:
Potassium, calcium, sodium, magnesium, aluminum, zinc, iron, tin, lead (hydrogen), copper, mercury, silver and platinum.
The fluidity of metals decreases in turn.
Second, the metal material 1. Pure metals copper, iron, aluminum and titanium
2. Definition of alloy: Alloys with metallic properties can be made by heating some metals or nonmetals in metals.
3. Common alloys: iron alloy, aluminum alloy and copper alloy.
Third, the nature of metals.
1. Physical characteristics: luster, electrical conductivity, thermal conductivity, ductility and flexibility.
2. Chemical properties: metal reacts with oxygen 4al+3o2 = = 2al2o3; 3Fe+2 O2 = = fe3o 4；
2mg+O2 = = 2 MgO； 2Cu+O2==2CuO
Metal reacts with acid mg+2hcl = = MgCl2+H2 =
Magnesium+sulfuric acid = = magnesium sulfate +H2
2Al+6 HCl== 2AlCl3+3H2↑
2Al+3H2SO4==2Al2(SO4)3+3H2↑
Zn+2HCl==ZnCl2+H2↑
Zn+2H2SO4==ZnSO4+H2↑
Fe+2 HCl = = FeCl 2+H2↑Fe+h2so 4 = = = feso 4+H2↑
Metal reacts with solution 2Al+3CuSO4==Al(SO4)+3Cu.
Copper+aluminum (sulfuric acid) = = copper (nitric acid) +2Ag
Fourthly, the utilization of metal resources.
1. Iron smelting: 1. Raw materials: iron ore, coke, air, limestone.
2. Principle: Fe2O3+3CO==2Fe|+3CO2
3. Equipment: blast furnace
2. Corrosion and protection of metals: 1. The rust of iron will change chemically with oxygen and water vapor.
2. Methods to prevent iron from rusting: 1. Drying; 2. Add a protective film; 3. Change its internal structure.
3. Protection measures for metal resources: 1. Prevent metal corrosion; 2. Recycling of metals; 3. Mining minerals in a planned and reasonable way; Looking for metal substitutes