Chemistry is a study of the composition, structure, properties of substances and their changing patterns of science.
I. Principles of access to medicines
1, the use of medicines to do the "three no's": can not use their hands in direct contact with medicines, can not put their nostrils to the mouth of the container to smell medicines, shall not taste the flavor of any medicine.
2, access to medicines to pay attention to the savings: access to medicines should be strictly in accordance with the amount of laboratory regulations, if there is no indication of the amount, generally take the smallest amount, that is, the liquid to take 1-2mL, as long as the solid cover the bottom of the test tube.
3, with the leftover drugs to do the "three no's": that is, can not be put back into the original bottle, do not discard, can not take out of the laboratory, to be put into the designated container.
4, the experiment if the eyes splashed into the liquid, to immediately rinse with water. Second, the access to solid medicines
1, lumpy or dense solid particles are generally taken with tweezers,
2, powdered or small particles of drugs with a key (or paper slot).
3, used tweezers or keys should be immediately wiped clean with clean paper.
Two, liquid drugs (stored in a fine-mouthed bottle) access
1, a small amount of liquid drugs access - with a rubber-tipped burette
The burette should be suspended vertically above the instrument, the liquid will be dripped into the instrument to receive the liquid, do not let the burette suction liquid burette contact with the wall of the instrument; do not lay the burette flat on the lab bench or other places, so as not to stain the burette; can not use the burette unwashed. ; can not use the unwashed dropper to suck another reagent (dropper on the dropper bottle can not be cross-used, and do not need to rinse)
2, from the fine-mouthed bottle when the test solution, should take off the stopper, inverted on the table; pouring the liquid, you should make the label toward the palm of the hand, the mouth of the bottle is close to the mouth of the test tube or the mouth of the instrument, to prevent residual residue in the bottle mouth of the liquid flow down to corrode the label.
3, the use of measuring cylinders
A, access to a certain volume of liquid medicines can be measured with a measuring cylinder.
Reading cylinder must be placed on a smooth, line of sight and the lowest level of the concave surface of the liquid in the cylinder. The reading is high when looking down and low when looking up.
B, measure the volume of liquid operation: first pour the liquid into the cylinder until close to the desired scale, and then add to the scale with a dropper.
Note: the measuring cylinder is a measuring device, can only be used to measure liquids, can not be used for long-term storage of medicines, and can not be used as a container for the reaction. It cannot be used to measure liquids that are too cold or too hot and should not be heated.
C. When reading, if you look up, the reading is lower than the actual volume; if you look down, the reading is higher than the actual volume.
Three, the use of alcohol lamp
1, alcohol lamp flame: three layers for the outer flame, inner flame, flame center.
The temperature of the outer flame is the highest, the inner flame temperature is the lowest, so heating should be placed on the outer flame part of the heated material.
2, the use of alcohol lamp precautions: A, alcohol in the alcohol lamp not more than 2/3 of the volume; B, after the use of alcohol lamps must be used to cover the lamp cap, can not be blown out with the mouth; C, absolutely prohibited to the burning alcohol lamps to add alcohol; D, absolutely prohibited to use the burning alcohol lamp to ignite another alcohol lamp, in order to avoid causing a fire. e, not use alcohol lamps, to cover the lamp cap, in order to prevent alcohol volatilization.
3, can be directly heated instruments are: test tubes, evaporating dishes, burning spoons, crucibles, etc.; can be heated instruments, but must be padded with asbestos mesh is a beaker, flasks; can not be heated instruments are: measuring cylinders, glass rods, gas cylinders.
4, to heat the drugs to dry the instrument, the first preheating, and then fixed in the drugs below the heating; heating solid drugs, drugs should be laid flat, the mouth of the test tube should be tilted slightly downward to prevent water from flowing back into the test tube and rupture the test tube; heating liquid drugs, the liquid volume can not be more than 1/3 of the volume of the test tube, the test tube should be upwardly tilted at an angle of 45 °, and can not be the mouth of the test tube to themselves! or others, washing instruments:
1, with a test tube brush, scrubbing, scrubbing must be rotated or move up and down the test tube brush, but the force can not be too strong, in order to prevent damage to the test tube.
2, the instrument washed clean sign is: glass instruments attached to the inner wall of the water is neither gathered into droplets, nor run down without strands.
Four, activity inquiry
1, on the candle and its burning inquiry: P7-P9
2, on the human body inhaled air and exhaled gas inquiry: P10-P12
Six, the characteristics of green chemistry: P6
Unit 2: around us air
I. Basic Concepts
1. Physical changes: changes that do not produce new substances. Such as the melting of paraffin, water evaporation
2, chemical changes: changes that produce new substances. Such as the combustion of substances, rusting of steel
The essential characteristics of chemical change: the generation of a basic concept
new substances. Chemical changes must be accompanied by physical changes, physical changes are not accompanied by chemical changes.
3. Physical properties: the properties that do not require a chemical change to manifest. Such as color, state, odor, density, solubility, volatility, hardness, melting point, boiling point, electrical conductivity, thermal conductivity, ductility and so on.
4, chemical properties: substances in the chemical changes in the performance of the nature (flammability, combustion, oxidation, reduction, stability). Such as iron is easy to rust, oxygen can support combustion.
5, pure matter: composed of only one substance. Such as N2 O2 CO2 P2O5.
6, mixture: by two or more substances mixed. Such as air, sucrose water, etc. (the components inside each maintain their original properties)
7, monomers: pure substances composed of the same element. Such as N2 O2 S P, etc.
8, compounds: pure matter composed of different elements. Such as CO2 KClO3 SO2 and so on.
9, oxide: by two elements of pure matter, one of the elements of the oxygen element of the compound. Such as CO2 SO2, etc.
10, chemical reaction: from two or more substances to produce another substance reaction. a + b == ab
11, decomposition reaction: from a reactant to produce two or more other substances reaction. ab === a + b
12, oxidation: the reaction of a substance with oxygen. (Slow oxidation is also an oxidation reaction.)
13, catalyst: in a chemical reaction can change the rate of chemical reaction of other substances, and its own quality and chemical properties before and after the reaction have not changed the substance. (also called catalyst) [should speak of a certain substance is a catalyst for a reaction, such as can not speak of manganese dioxide is a catalyst, but should speak of manganese dioxide is a catalyst for the decomposition of potassium chlorate reaction]
14, catalytic effect: the role of the catalyst in the reaction.
Two, the composition of air
1, the determination of the oxygen content of the air - the combustion of excess red phosphorus experiment P23
Question: (1) Why must red phosphorus in excess? (exhaustion of oxygen)
(2) Can substances such as sulfur, charcoal, and iron wire be used instead of red phosphorus? (No, new substances are produced)
2. Composition of air:
N2 : 78% O2 : 21% Rare gases : 0.94% CO2 : 0.03% Other gases and impurities : 0.03%
3. Uses of oxygen : supply for respiration and support for combustion
4. Uses of nitrogen : P24
5, Properties and uses of rare gases: P25
6. Pollution of the air: (air quality dailies, forecasts)
(1) Sources of pollution: mainly the combustion of fossil fuels (coal and oil, etc.) and the exhaust of factories, exhaust emissions from automobiles, and so on.
(2) Pollutants: mainly dust and gases. For example: SO2 CO oxides of nitrogen and so on.
Three, the nature of oxygen
1, the physical properties of oxygen: colorless and odorless gas, slightly denser than the density of air, not easily dissolved in water. Under certain conditions, it can be liquefied into a light blue liquid or solidified into a light blue solid.
2, the chemical properties of oxygen: chemical properties are more active, oxidizing, is a common oxidizer.
(1) can support combustion: tested with a wooden bar with a spark, the bar rekindles.
(2) Reaction of oxygen with some substances:
Participating substances Conditions of reaction with oxygen Phenomena of reaction with oxygen Names and chemical formulas of products Expressions of chemical reactions
Sulfur S + O2 ==SO2 (in air - light blue flame; in oxygen - violet-blue flame)
Aluminum foil 4Al + 3O2 == 2Al2O3
Carbon C + O2 == CO2
Iron 3Fe + 2O2 == Fe3O4 (burns violently with sparks, gives off a lot of heat, produces a black solid)
Phosphorus 4P + 5O2 == 2P2O5 (produces white smoke, produces a white solid P2O5)
Four, oxygen laboratory method
1, drugs: hydrogen peroxide and manganese dioxide or potassium permanganate or potassium chlorate and manganese dioxide
2, the principle of the reaction:
(1) hydrogen peroxide water + oxygen
(2) potassium permanganate manganese manganese dioxide + manganese dioxide + oxygen (the mouth of the conduit to be plugged with a piece of cotton)
(3) potassium chlorate Potassium chloride + oxygen
3, experimental setup P34, P35
4, collection methods: density than air - upward air displacement method (the mouth of the catheter should be stretched to the bottom of the cylinder, so as to facilitate the collection of air inside the cylinder to be driven out)
difficult to dissolve in water or not easily dissolved in water and do not react with water --drainage method (at the beginning of the bubble, because there is still air in the container or conduit can not be collected immediately, when the bubble continuous, uniform escape before starting to collect; when the bubble from the edge of the mouth of the cylinder, indicating that the gas has been collected full). The gas collected by this method is purer.
5. Procedure:
Check: check the gas tightness of the device. Such as P37
Fill: fill the test tube with the drug and plug the test tube tightly with a single-hole rubber stopper with a conduit.
Setting: fix the test tube on the iron stand
Pointing: light the alcohol lamp, first make the test tube evenly heated and then heat the part of the drug in the test tube.
Collection: collect oxygen by drainage method
Departure: after collection, evacuate the catheter from the sink first.
Out: extinguish the alcohol lamp.
6, test: with a spark of wood into the cylinder, if the wood rekindles, the gas in the bottle is oxygen.
7, check the full method:
(1) with the upward exhaust method of collection: the spark with a wooden bar on the mouth of the bottle, if the wooden bar rekindled, that the bottle is full of oxygen.
(2) When collecting by the drainage method: when bubbles rise from the edge of the mouth of the collecting cylinder, it means that the cylinder is full of oxygen.
8, Note:
(1) the mouth of the test tube should be tilted slightly downward (when solid medicines are heated), to prevent the water in the medicines from turning into water vapor after being heated, and then condensing into a droplet of water to flow back to the bottom of the test tube, which will make the test tube rupture.
(2) The catheter should not be extended too far into the test tube, but only slightly exposed to the rubber stopper, so that the gas can be easily discharged.
(3) The medicines in the test tube should be laid flat at the bottom of the test tube and heated evenly.
(4) The clamp should be placed in the upper center of the test tube (about 1/3 of the way from the mouth of the test tube).
(5) The outer flame of the alcohol lamp is to be used to heat the part of the drug; when heating, the alcohol lamp is first moved back and forth under the test tube so that the test tube is evenly heated, and then the drug part is heated.
(6) When collecting gas by the drainage method, the cylinder is filled with water and then placed upside down in the sink (the mouth of the cylinder should be under the surface of the water), and the catheter can be stretched to the mouth of the cylinder; when collecting gas by the upward air venting method, the cylinder is placed squarely, and the mouth of the catheter should be close to the bottom of the cylinder.
(7) When collecting gas by the drainage method, care should be taken to collect the gas when the bubbles are released continuously and evenly from the mouth of the catheter, otherwise the collected gas is mixed with air. When bubbles come out of the mouth of the collecting cylinder, it is proved to be full.
(8) When stopping the reaction, the withdrawal catheter should be put first, and the alcohol lamp should be moved later (to prevent the water in the sink from pouring into the test tube, causing the embassy to rupture)
(9) The collecting cylinder full of oxygen should be placed squarely, and the mouth of the cylinder should be covered with a piece of glass.
(10) A small ball of cotton should be stuffed in the mouth of the test tube when making oxygen with potassium permanganate.
V. Industrial Method of Oxygen Production - Separation of Liquid Air Method
Pressurized at low temperatures, air is converted to liquid air and then evaporated. Because the boiling point of liquid nitrogen is lower than that of liquid oxygen, nitrogen is first evaporated from liquid air, and what remains is mainly liquid nitrogen.
Unit III: Water in Nature
I. Composition of Water
1, electrolysis of water experiment: electrolysis of water is a chemical reaction under the action of direct current. Water molecules decomposed into hydrogen atoms and oxygen atoms, these two atoms were two and two constitute into hydrogen molecules, oxygen molecules, many hydrogen molecules, oxygen molecules gathered into hydrogen, oxygen.
2, a positive oxygen, two negative hydrogen
Experiment Phenomenon Expression
Electrolysis of water test Bubbles on the electrode, the positive and negative gas volume ratio of 1: 2. Negative gas can be combustible, the positive gas can be made to rekindle a wooden bar with sparks. Water Oxygen + hydrogen (decomposition reaction)
2H2O Electrification 2H2↑ + O2 ↑
3. From the macro analysis, water is composed of hydrogen and oxygen elements, water is a compound. From the microscopic analysis, water is composed of water molecules, water molecules are composed of hydrogen atoms, oxygen atoms.
4, the nature of water
(1) physical properties: colorless, odorless, tasteless liquid, boiling point is 100 ° C, freezing point is 0 ° C, the density of 1g/cm3, can dissolve a variety of substances to form a solution.
(2) chemical properties: water can be decomposed into hydrogen and oxygen under the condition of electricity, water can also be reacted with many monomers (metal, non-metal), oxides (metal oxides, non-metal oxides), salt and many other substances.
Two, hydrogen
1, physical properties: colorless and odorless gas, insoluble in water, density is smaller than air, is the smallest density under the same conditions of the gas.
2, chemical properties - flammable.
Burning in air (or oxygen) gives off a lot of heat, the flame is light blue, the only product is water.
Note: The mixture of hydrogen and air (or oxygen) may explode when exposed to open flames, so it must be tested for purity before igniting it. (The method of testing purity: collect a test tube of hydrogen, block the mouth of the test tube with your thumb, the bottle moved down into the flame of the alcohol lamp, release your thumb to ignite, if a sharp popping sound indicates that the hydrogen is impure, and need to be collected again, and then tested; the sound is very small, it means that the hydrogen is more pure.)
Three, molecules
1, definition: molecules are the smallest particles that maintain the chemical properties of matter.
2, the characteristics of molecules:
(1) molecules are very small, the mass and volume are very small
(2) molecules are always in constant motion, and the higher the temperature, the greater the energy of the molecules, the faster the speed of movement.
(3) There are forces and intervals between molecules. The total volume of different liquids mixed is usually not equal to the volume of several liquids simply added, is because there are certain intermolecular forces and spacing. (Thermal expansion and contraction)
3, explain in daily life, encountered these phenomena::
a: passing by the door of the winery, did not drink, but can smell the aroma of wine?
b: working in a cigarette factory, although not smoking, but the body has a smell of smoke?
c: After the clothes are washed and dried, the wet clothes become dry. So, where does the water go?
d: Sugar is put in water and disappears, but the water has a sweet taste. Why?
e: Half a cup of alcohol is poured into half a cup of water, but the cup is not full. What happened?
Four, atoms
1, definition: atoms are the smallest particles in chemical change
2, the essence of chemical change: the differentiation of molecules and the recombination of atoms.
3. Comparison of molecules and atoms:
Atoms Molecules Remarks
Concepts The smallest particles in a chemical change The smallest particles that maintain the chemical properties of a substance. Must atoms be smaller than molecules?
Similarity Small, light, and spaced.
The same kind of atom has the same properties;
Different kinds of atoms have different properties; small, light, spaced. Same molecule of the same kind with the same properties;
different molecules of different kinds with different properties;
dissimilarity Cannot be subdivided in a chemical reaction. In a chemical reaction, splitting into atoms, from which the atoms recombine to form new molecules.
Interrelationships Atoms can form molecules, from which molecules form substances. E.g. oxygen, nitrogen, etc. Atoms can also form substances directly. E.g. metals Molecules are made up of atoms.
Numerous more molecules of the same kind make up matter. How many kinds of particles make up matter?
V. Classification, composition, composition of matter
1, matter consists of elements
2, the particles that make up matter are: molecules, atoms, ions
3, the classification of substances, monomers, pure substances, compounds, mixtures
6, the purification of water
1, the purification of water (1), adding flocculants adsorption impurities (adsorption) Precipitation) (2), filtration (3), disinfection (add chlorine or dichloromethane)
2, the role of activated carbon water purification: has a porous structure, gas, steam or colloidal solids have a strong adsorption capacity. It can adsorb pigment and make the liquid colorless, and it can also remove odor.
3, hard water and soft water
(1) difference: the water contains soluble calcium, magnesium compounds.
(2) the softening method of hard water: boiling or distillation
seven, the method of classification of substances
1, filtration: separation of soluble and insoluble substances composed of mixtures (Note: "a paste" "two low") "three rely on")
2, distillation: separation of boiling points of different substances composed of a mixture
Eight, care of water resources
1, human-owned water resources P57-P59
2, China's water resources and water pollution: The main sources of water pollution: industrial pollution, agricultural pollution, living pollution.
3, caring for water resources - water conservation signs
(1) saving water, improve water utilization rate saving water, on the one hand, to prevent the waste of water, on the other hand, to reduce the large amount of industrial, agricultural and domestic water use through the use of new technologies, reform processes and change habits to improve the utilization rate of water.
(2) Ways to prevent and control pollution of water bodies: A. Reducing the production of pollutants B. Treating polluted water bodies to make them meet discharge standards C. Promoting the use of farmyard manure in agriculture and the rational use of chemical fertilizers and pesticides D. Centralizing the treatment of domestic sewage before discharging it.
Unit IV The Wonders of the Composition of Matter
I. The Composition of Atoms:
Proton: 1 proton with 1 unit of positive charge
Nucleus (+)
Neutron: uncharged
Atom
uncharged Electrons (a) 1 electron with 1 unit of negative charge
1. There are three kinds of particles: protons, neutrons, and electrons. But not all atoms are composed of these three particles. For example, one type of hydrogen atom has only protons and electrons, not neutrons.
2. In an atom, the number of positive charges carried by the nucleus (nuclear charge) is the number of charges carried by the proton (neutron is not charged), and each proton carries 1 unit of positive charge, therefore, the number of nuclear charges = the number of protons, due to the number of protons in the nucleus of the atom and the number of electrons outside the nucleus is equal to the number of nuclear charges = the number of protons = number of electrons outside the nucleus, so the number of nuclear charges = protons = the number of electrons in the atom.
There are charged particles in an atom, why is the whole atom not electrically charged?
Atoms are composed of a positively charged nucleus at the center of the atom and negatively charged electrons outside the nucleus, the nucleus is composed of protons and neutrons, protons are positively charged, neutrons are not charged; the nucleus of the atom carries a positive charge (number of nuclear charges) and the electrons outside the nucleus carries a negative charge equal to the electrons, but the electrical nature of the opposite, so the whole atom is not electrically active.
Two: Relative Atomic Mass: - Internationally, the mass of a carbon atom 1/12 as a standard, the mass of other atoms and it compared to the ratio obtained as the relative atomic mass of this atom.
The relative atomic mass of an atom of an element = the actual mass of an atom of an element / (the actual mass of the carbon atom × 1/12)
Note:
1. Relative atomic mass is only a ratio, not the actual mass of the atom. Its unit is 1, which is omitted .
2. In the relative atomic mass calculations, a carbon atom chosen is carbon 12, a carbon atom containing 6 protons and 6 neutrons, and its mass of 1/12 is approximately equal to 1.66 × 10-27 kg.
Three, elements:
1. Definition: a general term for a class of atoms with the same nuclear charge (i.e., the number of protons in the nucleus).
2, the order of content of elements in the earth's crust: O Si Al Fe
the most abundant non-metallic elements The most abundant metallic elements
3, the elements, the difference between the atoms and the connection
elements Atom
Concepts With the same number of nuclear charges of a class of atoms of a general term. The smallest particle in a chemical change.
Distinction Speaking only of species, not the number, there is no significance of the number of more or less. That is, speak of kinds, have speak of number, have the meaning of quantity more or less.
Scope of use Applied to describe the macroscopic composition of matter. Applied to describe the microscopic composition of matter.
Examples E.g. Water contains the elements hydrogen and oxygen. I.e.. Water is composed of the elements hydrogen and oxygen. E.g.; A water molecule, is composed of two hydrogen atoms and one oxygen atom.
Contact The smallest particle of an element
Element ================================= atom
A general term for a class of atoms
4. Meaning of the symbols of the elements: A. Indicates an element.B. The table is an atom of such an element
Example: significance of O. N. Meaning:
5, the writing of element symbols: remember the symbols of common elements
metal elements
6, classification of elements
non-metallic elements liquid solid gaseous gaseous rare gases elements
7, the periodic table of the elements
four, ions
1, the arrangement of electrons outside the nucleus step -- expressed in terms of the atomic structure schematic of the elements
2. Understanding the significance of the atomic structure schematic -- the atomic structure schematic of elements 1-18
3. The relationship between the properties of the elements and the number of outermost electrons
< p>A, rare gas elements: the number of electrons in the outermost layer is 8 (helium is 2) stable structure, stable properties.B, metal elements: the number of electrons in the outermost layer is generally less than 4, easy to lose electrons.
C, non-metallic elements: the number of outermost electrons is generally more than or equal to 4, easy to gain electrons.
4, the formation of ions: atoms gain or lose electrons after the formation of charged atoms
Atoms gain electrons - negatively charged - the formation of anions
Atoms lose electrons - positively charged - the formation of cations
5 The representation of ions - Ionic symbols. Ion symbol representation Xn+ or Xn-, X indicates the chemical formula of the element symbol or atomic group, X the upper right corner of the "+" or "-" indicates that the ion is positively or negatively charged, "n " indicates a charge of n units. For example, Al3+ indicates one aluminum ion with three units of positive charge; 3SO42- indicates three sulfate ions with two units of negative charge.
V. Chemical formula
1. Definition: the symbols of the elements to indicate the composition of the substance formula.
2, meaning:
(1). Indicates a substance;
(2). Indicates the elements that make up this substance;
(3). Indicates the ratio of the number of atoms of various elements;
(4). Indicates a molecule of this substance (for substances composed of molecules).
For example, the meaning of HO2 indicates that: water is composed of hydrogen and oxygen elements;
Water is composed of water molecules;
Water molecules are composed of hydrogen and oxygen atoms;
A water molecule is composed of 2 hydrogen atoms and 1 oxygen atom
Sixth, the valence
1, O is usually show -2 price, hydrogen usually +1; metal elements usually show positive valence; the valence of the chemical combination has a variable valence.
2, the application of valency: based on the compound of the elements in the valency of the algebraic sum of 0.
3, write the chemical formula according to the valency of the positive and negative, according to the left positive and right negative ammonia special to write.
4, remember the valence of common elements
seven, 1, the number in front of the symbol of the element: the number of atoms 2N
2, the number in front of the chemical formula: the number of molecules 2H2O
3, the number in front of the symbol of the ion: the number of ions
4, the number of the upper right corner of the symbol of the element: the charge that the ion carries Mg2+
5, the number directly above the element symbol: the element's valence
6, the chemical formula in the lower-right corner of the element symbol: the number of atoms contained in the molecule H2O
eight, the relative molecular mass:: the sum of the relative atomic mass of the atoms in the chemical formula
e.g.: the relative molecular mass of H2O = 1 × 2 + 16 = 18 The relative molecular mass of CO2 = 12 + 16 × 2 = 44
The relative molecular mass of NaCl = 23 + 35.5 = 58.5 The relative molecular mass of KClO3 = 39 + 35.5 + 16 × 3 = 122.5
According to the chemical formula, you can also calculate the ratio of mass of the elements in the compound.
For example, in H2O, the mass ratio of hydrogen to oxygen is:: 1×2:16=2:16=1:8
In CO2, the mass ratio of carbon to oxygen is:: 12:16×2=12:32=3:8
For example, calculate the mass fraction of nitrogen in the chemical fertilizer ammonium nitrate (NH4NO3)
First, calculate the relative molecular weight of ammonium nitrate. Calculate the relative molecular mass of ammonium nitrate = 14 + 1 × 4 + 14 + 16 × 3 = 80
2. Then calculate the mass fraction of elemental nitrogen:
Unit VI: Carbon and Carbon Oxides
I. A few monomers of Carbon
1. Diamond (dispersion is good, hard)
2. Graphite (soft, slippery. Conductive, heat resistant)
3. C60 (made up of molecules)
Properties: 1. inactive at room temperature
2. flammable C+ O2== (ignited) CO2 2C+ O2== 2CO
3. reducing C+2CuO== 2Cu+ CO2
4. amorphous carbon 1. charcoal and activated carbon Adsorption
2. Coke steelmaking
3. Carbon black pigment
2. Laboratory production of CO 2
1. Physical Properties: Normally a colorless and odorless gas, slightly denser than air, soluble in water
Chemical Properties: Normally cannot be burned, nor does it support combustion, and it cannot be supplied for respiration
With water Reaction CO2+ H2O== H2+ CO3
Reaction with lime water CO2+Ca(OH)2==CaCO3+ H2O
2. Limestone (or marble) and dilute hydrochloric acid
3. Principle of CaCO3 + 2HCl == CaCl2 + H2O + CO2
4. Experimental setup: solid-liquid at room temperature <
Collection method upward air exhaust method
5. test: (verification) with clarified lime water (check full) burning wooden bar placed in the mouth of the cylinder
6. uses: fire extinguishing, gas fertilizer, chemical raw materials, dry ice for artificial rainfall and refrigerants
three, the nature of the CO
1. physical properties: usually colorless and odorless gas, slightly denser than air, the density of the gas is very low. Gas, slightly less dense than air, insoluble in water
Chemical properties: flammable 2CO + O2 == 2CO2
Reducing CO + CuO == Cu + CO2
Toxicity: poisoning due to lack of oxygen
Unit VII Fuels and their role
I. Conditions of combustion
1. flammable materials
2. oxygen (or air)
3. reach the minimum temperature required for combustion (also called the ignition point)
II. Principles and Methods of Extinguishing Fire
1. removing combustibles or isolating combustibles from other objects
2. isolating oxygen and air
3. is the temperature down to a little below the ignition point
III, Fossil fuels: coal, oil and natural gas
Impact of fossil fuels on the air: burning coal and gasoline pollutes the air
IV. Clean fuels: ethanol and natural gas
V. Energy sources 1. fossil fuels 2. hydrogen 3. solar energy 4. nuclear energy
These energy sources are being developed and utilized to not only partially solve the problem of fossil fuels running out, but to reduce pollution to the environment.
Unit VIII: Metals and Metallic Materials
I. Order of Metals Activity Table:
K Ca Na Mg Al Zn Fe Sn Pb (H) Cu Hg Ag Pt Au
Metal Activity Decreases in Order
II. Definition of alloy: in the metal heating and certain metals or non-metals, you can make alloys with metal characteristics.
3. Common alloys: iron alloys, aluminum alloys, copper alloys.
Three, metal properties
1. Physical properties: shiny, can conduct electricity, can conduct heat, ductility, curvature
2. Chemical properties: metal and oxygen reaction 4Al + 3O2 == 2Al2O3; 3Fe + 2O2 == Fe3O4;
2Mg + O2 == 2MgO;2Cu + O2 ==2CuO
Metals react with acids Mg+ 2HCl==MgCl2+H2↑
Mg+ H2SO4==MgSO4+H2↑
2Al+6 HCl== 2AlCl3+3H2↑
2Al+3H2SO4==2Al2(SO4)3+3H2↑
Zn+ 2HCl==ZnCl2O;
2Mg+O2==2MgO; 2Cu+O2==2CuO. 2HCl==ZnCl2+H2↑
Zn+2H2SO4==ZnSO4+H2↑
Fe+2HCl==FeCl2+H2↑ Fe+H2SO4==FeSO4+H2↑
Metals reacting with solutions 2Al+3CuSO4==Al(SO4)+3Cu
Cu+ Al(SO4)==Cu(NO3)+2Ag
IV. 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: 1. Conditions of rusting of iron Chemical changes with oxygen and water vapor, etc.
2. Methods of preventing rusting of iron: 1. drying, 2. adding a layer of protective film, 3. changing the internal structure
3. Measures for the protection of metal resources: 1. preventing corrosion of metals; 2. recycling of metals; 3. planned and rational extraction of minerals; 4. looking for substitutes for metals
3. p>