Unit 1 Into the world of chemistry
Topic 1 Chemistry makes the world more colorful
⒈. Chemistry is the study of matter and its science. An important way to learn chemistry is , is an important means of scientific inquiry.
peak atomic and molecular doctrines. and other scientists have come to an important conclusion: matter is composed of and; molecular and the recombination of the basis of chemical change, that is, in chemical change will break down, and will not break down, but can be recombined into a new molecule, that is, the atom is the smallest particles to participate in chemical change.
3 the basic components of matter - elements. Mendeleev discovered and , making the study and research of chemistry regular.
Sung the main features of green chemistry.
(1) Making full use of resources and energy and using non-toxic and harmless raw materials.
(2) Carrying out chemical reactions under non-toxic and non-hazardous conditions to minimize the discharge of waste into the environment.
(3) Increase the utilization rate of atoms, trying to make all the atoms used as raw materials to be accepted by the product, and realize "zero emission".
(4) To produce environmentally friendly products that contribute to environmental protection, community safety, and human health.
Be careful to understand several high-tech chemical products, such as super-plastic ductility; water-insulating and breathable polymer film; kittens sitting serenely on a plate heated by a high-temperature flame, also polymer chemical materials, which is characterized by the nature of the adiabatic; super-strong tensile strength of the nylon rope, and so on.
Select an egg washed and placed in a cup filled with vinegar, the phenomenon observed is , the reason for this is , indicating what substances are in the egg shell .
Subject 2 Chemistry is a science based on experimentation
(When the following substances are involved, the chemical formula is written)
I. Investigation of candles and their combustion
Conclusion: (1) Candles are usually yellowish-white solids with a density greater than that of water , which dissolves in water
(2) (1) Candles emit yellowish-white flames, exothermic, luminous, and the candles are gradually becoming shorter and shorter, which melt when heated. It melts when heated and solidifies when cooled.
②The part of the wooden bar that is in the outer flame is the first to turn black, and the temperature of the outer flame is the most .
③ beaker wall of water mist appeared, indicating that the candle generated, which contains elements; candle combustion is also generated, the gas can make the change, that the candle contains elements.
④ black powder appears on the white porcelain plate, which further indicates that the candle contains elements.
The chemical reaction formula for candle combustion is:
(3) There is a white smoke that can be re-burned. This indicates that the candle burning is the candle vapor that is ignited by the vaporization of the candle.
Second, what is the difference between the air inhaled and exhaled gas inquiry
Conclusion: 1. Exhaled gas to make the lime water appears more turbid, proving that the exhaled gas is higher than the air content.
2. The exhaled gas puts out the burning stick of wood, and the burning stick of wood burns in the air, proving that the content of oxygen in the air is higher than that of oxygen in the exhaled gas.
3. The water mist on the glass piece exhaled against is more than the water mist on the glass piece placed in the air, proving that the content of water in the exhaled gas is higher than the content of water in the air.
Subject 3 into the chemical laboratory
1. Drugs to take
(1) drugs to take the "three" principle:
① "three do not principle": can not use their hands to take the drugs; can not put their nostrils close to the mouth of the container to smell the odor of the drugs; the "three do not principle": can not use their hands to hold the drugs; can not put the nose close to the mouth of the container to smell the odor of the drugs. Container mouth to smell the smell of drugs; not to taste the flavor of any drug.
② principle of economy: strictly according to the experimental dosage of drugs. If there is no indication of dosage, generally take the smallest amount, liquid lmL ~ 2mL, solid as long as the bottom of the test tube covered.
③ principle of disposal: the remaining drugs in the experiment can not be put back into the original bottle; do not discard; not to take out the laboratory.
(2) the method of taking drugs (to the test tube to add solid drugs or pouring liquid drugs)
solid drugs: ① block: with a clip; the operation is: "a flat, two put, three slow vertical" (will be placed horizontally test tube. Use tweezers to put a solid block of medicine into the mouth of the test tube, and then slowly stand up the test tube, so that the block of solid slowly slide to the bottom of the test tube).
② powder: take with (or ); the operation is: "a tilt, two send, three upright" (tilt the test tube, the medicine spoon or paper slot containing the drug into the bottom of the test tube Shao, and then make the test tube upright, so that the drug falls to the bottom of the test tube).
Liquid medicines: the operation is: "Remove the cork and put it on the label, pour it slowly, and put the cap tightly in place after use."
(3) the method of measuring the volume of liquid with a cylinder: ① reading, the cylinder should be placed smoothly, and make the line of sight and the concave surface of the liquid level at the most, ② should be based on the volume of liquid volume, the use of the appropriate size of the cylinder.
2. Substance heating.
(1) the use of alcohol lamps: ① prohibit the addition of ethanol to the alcohol lamp; ② to use a match to ignite, prohibit the use of another alcohol lamp lit; ③ heating; ④ extinguished with the use of extinguish, can not be blown out with the mouth; ⑤ the amount of alcohol can not be more than the volume of alcohol lamps, 2 / 3, not less than 1/4.
(2) to the material heating methods and precautions: ① heating glass instruments, to dry the water outside the container wall; ② very hot containers do not immediately rinse with cold water. In order to avoid uneven heating and rupture; ③ to the liquid test tube heating, the amount of liquid in the test tube can not exceed the volume of the test tube; ④ heating should be the first test tube; ⑤ test tube should be placed on the outer flame; ⑥ test tube mouth can not be directed in the direction of; ⑦ to the test tube of the solid medicine heating, the mouth of the test tube should be slightly inclined to the test tube, the heat uniformity and then fixed heating.
(3) to the liquid substances can be heated instrument test tubes, beakers, flasks, etc.; to the solid substances, can be used to heat a dry test tube.
3. Washing of glass instruments.
Washing method: ① pour the waste (to be poured in the designated container); ② rinse with water and vibration; ③ brush with a test tube; ④ and then rinse with water. If the inner wall of the glass instrument is attached to insoluble alkali, carbonate, alkaline oxides, etc., can be dissolved with dilute hydrochloric acid, and then rinsed with water; if the inner wall of the glass instrument is attached to the oil, a small amount of alkali solution or washing soda can be used to scrub, and then rinsed with water.
4. The correct use of the balance is: object code, weighing: M object = M code M travel code
If accidentally made: object code, weighing: M object = M code M travel code
5. The two chemical experiments in this lesson are (write the chemical reaction equation, and label the color of the substance):
(1) sodium hydroxide + copper sulfate:
( ) ( )
(2)
Unit 2 The Air Around Us
Topic 1 Air
I. Air is a natural resource, well-mixed and relatively stable
1. Main components and composition of air (by volume):
Components of air Nitrogen Oxygen Rare gases Carbon dioxide Other gases and impurities
Volume fractions 0.94% 0.03%
2. Uses of oxygen, nitrogen and rare gases.
Oxygen ①Animal and plant respiration ②Medical emergency ③Metal cutting ④Steel making ⑤Space navigation, etc.
Nitrogen ①Superconducting experimental vehicle ②Chemical raw materials ③As a protective gas ④Food nitrogen as a preservative, etc.
Rare gases ①Protective gas ②Make a variety of uses of the electric light ③Laser technology ④Liquid helium cryostat, etc.
3. The composition of the air determination of the chemical reaction Equation:
II. Air protection:
4. Air pollution and its prevention.
(1) Sources of air pollution: harmful gases ( , , , ) and soot (dust and dirt).
(2) Hazards: ① serious damage to human health, ② affect the growth of crops, ③ damage to the ecological balance; ④ lead to global warming, destruction of the ozone layer and acid rain.
(3) preventive measures: ① strengthen the monitoring of atmospheric quality; ② improve environmental conditions; ③ use of clean energy; ④ active planting of trees, afforestation, grass planting and so on.
III. Pure matter mixtures
5. Pure matter is composed of a substance, such as oxygen ( ), hydrogen ( ), nitrogen ( ), sodium chloride ( ) and so on.
6. Mixtures are made up of two or more substances mixed together, there is no reaction between these substances, each maintains its original properties. For example, nitrogen and oxygen in air.
7. How to distinguish between pure substances and mixtures:
Mixtures: containing at least two pure substances, each pure substance has its own chemical formula, so mixtures generally can not be expressed in a chemical formula. Such as salt water (by salt () and water () two pure substances dissolved and mixed, air (by nitrogen (), oxygen (), carbon dioxide (), rare gases and other substances.
Purity: contains only a fixed substance, has its own kind of chemical formula. Such as calcium carbonate ( ), sodium sulfate ( ), potassium permanganate ( ), chlorine ( ), nitrogen ( ) and so on.
IV. Physical properties are the properties of a substance that can be expressed without a chemical reaction, such as color, state, smell, melting point, boiling point, hardness, density, solubility, etc.
Lesson 2 Oxygen
1. Physical properties of oxygen.
Usually it is a colorless, odorless gas that dissolves in water and is slightly denser than air.
2. Chemical properties of oxygen.
Oxygen is a chemically active gas, under certain conditions can be chemically reacted with many substances, while releasing heat. Oxygen has oxidizing properties, is a common oxidizing agent. Oxygen is flammable and can support combustion.
Write the equation of a chemical reaction that you know involves oxygen:
3. Changes in matter-physical and chemical changes.
Physical changes Chemical changes
Concepts Changes in which no other substances are produced Changes in which other substances are produced
Accompanying phenomena Changes in shape, state, etc., of a substance are often accompanied by exothermic effects, glowing, discoloration, release of gases, production of precipitates, etc.
Essential differences Whether or not other substances are produced at the time of the change
Examples Paraffin wax melts, water freezes, gasoline evaporates. Water melts, water freezes, gasoline evaporates, coal burns, iron rusts, food spoils
Interrelationships Physical changes must accompany chemical changes in substances, such as paraffin wax burning preceded by paraffin wax melting phenomenon
4. Properties of substances-physical properties and chemical properties.
Physical Properties Chemical Properties
Concepts Properties that a substance exhibits without undergoing a chemical change Properties that a substance exhibits during a chemical change
Substance Properties that a substance exhibits when the structure of its particles remains unchanged. Properties of a substance that appear when its particle structure is changed.
Examples Color, state, odor, melting point, boiling point, hardness, density, solubility, volatility, adsorption, electrical conductivity, thermal conductivity, ductility, etc. Flammability, oxidation, stability, flammability, reduction, acidity, alkalinity, etc.
Determination Directly by the senses or measured by an instrument, and can be known by a chemical change
Difference Whether or not it needs to be manifested by a chemical reaction.
5. Several chemical concepts:
(1) Chemistry: the reaction of two or more substances to produce another substance is called a chemical reaction.
It can be expressed as: A + B + ...... → E (referred to as "all-in-one")
Write five chemical equations for the chemical reaction:
(2) oxidation: the chemical reaction that occurs when a substance reacts with oxygen is called an oxidation reaction. oxidation reaction. (Oxygen here means both oxygen and other substances containing oxygen).
(3) slow oxidation: it is a non-luminous oxidation reaction that proceeds slowly and imperceptibly. Such as breathing, rusting of steel, etc. There is heat emission.
(4) Oxides: pure substances like phosphorus pentoxide, carbon dioxide, sulphur dioxide, etc. composed of oxygen and another element.
6. A comparison of the combustion phenomena of various substances in air and oxygen is shown in the table below
Substances Air Oxygen
Phosphorus Produces a lot of white smoke Bright fire, produces a lot of white smoke
Reaction Equation
Sulfur Emits a weak light blue flame, gives off heat and forms a gas with a pungent odor Gives off a bluish-purple flame, gives off heat, and produces a gas with a pungent odor
Equation
Carbonwood Continuously red-hot, smokeless, and flameless Intensely burns, emits a white light, gives off heat, and produces a gas that muddies clarified lime water
Equation
Aluminum foil Difficultly burns Intensely burns, emits a bright white light, gives off heat, and produces a white solid
Equation
The reaction equation <
Iron wire does not burn burns intensely, emits a brilliant white light, gives off heat, and produces a black solid
Equation
Subject 3: Oxygen Production
1. Oxygen is often made in the laboratory by decomposing hydrogen peroxide solution or by heating potassium permanganate.
a.2H2O2 MnO2 2H2O+ O2↑
Please point out that the reactants in this reaction are: , the reaction conditions are: , and the products are
MnO2 acts as in this reaction. It is characterized by the fact that although it takes part in the chemical reaction, its and
remain unchanged, and its role is to change the chemical reaction .
b.2KMnO4 heating K2MnO4 + MnO2 + O2↑
Draw the diagram of this device for the production of oxygen, and indicate the name of the apparatus:
2. Industrial production of oxygen:
(1) Separation of liquid air - physical changes
( 2)Oxygen-rich membrane separation technology--oxygen-rich air
3. 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 called catalyst,
catalytic effect: the role of the catalyst in a chemical reaction is called catalysis.
4. Decomposition: the reaction in which a substance produces two or more other substances is called a decomposition reaction.
The decomposition reaction can be expressed as A → B + C + ...... (referred to as "one into many").
Write five chemical equations for decomposition reactions:
Unit 3: Water in Nature
Subject 1: Composition of Water
I. Physical Properties of Hydrogen:
Hydrogen is a colorless, odorless, water-soluble, very dense gas.
II. Chemical properties of hydrogen:
1. Hydrogen is flammable, can burn in air or oxygen, emitting a light blue flame.
Chemical reaction equation:
Uses of hydrogen utilizing this property:
2. Hydrogen has reducing properties:
For example, hydrogen reduces copper oxide:
Label the oxidizing agent, reducing agent in this reaction:
Hydrogen reduces iron oxide:
Uses of hydrogen utilizing this property:
3. Hydrogen mixed with air or oxygen may explode when it meets an open flame. When using hydrogen, pay attention to safety and always before ignition .
The test of hydrogen purity of force method is: collect a small test tube of hydrogen, block the mouth of the test tube with your thumb, move closer to the flame of the alcohol lamp, remove the thumb ignition. If you hear a sharp popping sound, it means that hydrogen is impure; if the sound is very small, it means that hydrogen is more pure.
III. Laboratory Preparation of Hydrogen:
1. Principle of the experiment:
2. Experimental setup (drawings):
3. To the best of your knowledge, what are the characteristics of a metal that can displace hydrogen from an acid:
IV. Monomers and compounds
1. Monomers are pure substances composed of the same elements. For example, hydrogen (H2), oxygen (O2), and nitrogen (N2).
2. Compounds are pure substances composed of different elements. Such as carbon dioxide (CO2), water (H2O), phosphorus pentoxide (P2O5) and so on.
Comparison of monomers and compounds
Concepts Examples Distinctions Similarities
Monomers Pure substances composed of the same elements Hydrogen (H2) Oxygen (O2) Pure substances composed of the same elements
Compounds Pure substances composed of different elements Water (H2O), Carbon dioxide (CO2) Different elements Pure substances
3. The most direct distinction between monomers and compounds is made from the composition, pure substances composed of only one element are monomers, such as iron, aluminum, carbon, sulfur, etc.; and pure substances composed of two or more elements are compounds. Or it can be seen from the name, such as carbon dioxide, potassium permanganate and so on. Also, monomers generally cannot be decomposed, whereas compounds may decompose into two or more substances under certain conditions.
Subject 2 Molecules and Atoms
1. Matter is made up of many tiny particles that are invisible to the naked eye - , , , .
2. Properties of molecules: the mass and volume of molecules are very small, molecules are always in constant motion, the higher the temperature, the molecular energy increases, the rate of movement accelerated, the molecules have a certain interval between.
The same kind of molecules have the same properties, different kinds of molecules have different properties.
3. By the molecular composition of the material in the physical change, the molecules themselves change, only the spacing between the molecules changed, so that the state of matter changed.
When a substance made up of molecules undergoes a chemical change, the molecules of the original substance are changed, and other new molecules are created.
4. Molecules are; molecules are made of.
In a chemical change, what changes is , what does not change. In a chemical change it cannot be divided into smaller particles.
5. Atoms are the smallest particles in a chemical change. Metals, rare gases, diamond, monocrystalline silicon, etc. are made directly from atoms.
6. Explain pure substances and mixtures in terms of molecule-atom theory: substances made up of molecules
are pure, and substances made up of molecules are mixtures; and the particles of the various different substances in the mixtures
do not change chemically with each other.
Subject 3 Purification of Water
1. Filtration is a method of separating insoluble solids from liquids, and is used to leave solid impurities that are insoluble in water with water.
(1) filtration operation to do "a stick, two low, three rely on":
a stick: the filter paper close to the funnel wall, do not leave bubbles
two low: a. the funnel filter paper edge is lower than the edge of the funnel mouth
b. the funnel liquid surface is lower than the edge of the filter paper
Three rely on: a. Pouring liquid, beaker and glass rod contact
b. The end of the glass rod and the funnel three layers of filter paper in contact
c. The lower end of the funnel and the filtrate to receive the contact with the inner wall of the beaker
(2) through the filtration of filtrate is still turbid possible reasons: ① broken filter paper; ② filtrate edge is higher than the edge of the paper; ③ instrumentation is not clean and so on. Still turbid filtrate should be filtered again until clarified.
The following items can be used in daily life instead of the laboratory filter to filter liquids. Such as gravel filter layer, activated carbon layer, fluffy cotton, gauze and so on.
2. Activated charcoal can filter out insoluble substances in the liquid as well as adsorb away some dissolved impurities.
3. Methods of purifying water include: and other methods.
If a single operation, the relative degree of purification from low to high order is:
4. Containing more soluble calcium and magnesium compounds of water called water; does not contain or contain less soluble calcium and magnesium compounds of water called water.
(1) hard water and soft water differentiation methods:
①Heating or long placed in the water scale is water.
② add soapy water to the water, the foam is very little water, a large number of foam water is water.
(2) hard water to life and production hazards:
① wash clothes with hard water is a waste of soap, but also can not wash the clothes, over time will make the clothes hard.
② boiler, with hard water easy to make the boiler scale, not only waste of fuel, may cause a serious explosion.
(3) hard water softening methods:
①Life by boiling or exposing the water.
②In the laboratory by making distilled water.
Topic 4 Caring for Water Resources
1. The total amount of water on Earth is large, but there are few freshwater resources available.
2. The natural world of water, including ocean water (accounting for the global water reserves, and seawater is rich in chemical resources, according to the current determination, seawater contains a variety of chemical elements), lake water, river water, groundwater, atmospheric water, biological water and so on.
3. Many countries and regions of the world are facing a water shortage crisis is due to:
Freshwater resources are not abundant, freshwater only about the global reserves of freshwater, can be utilized only about one of them,
less than 1% of the total amount of water, and the distribution is uneven, pollution is becoming more and more serious.
China's total water resources 2.8X1012m3, ranking first in the world. But the per capita water is only about 2300m3, about the world's per capita water, ranking first in the world.
4. The main sources of water pollution: industrial production of wastewater is not discharged; agricultural fertilizers, pesticides, the irrational use of domestic sewage discharge.
5. The measures to protect water resources are, on the one hand, to conserve water and improve the utilization rate of water; on the other hand, to prevent water pollution.
6. The measures to prevent and eliminate water pollution are:
(1) Reduce the production of pollutants.
(2) Treatment of polluted water to make it meet discharge standards.
(3) Promote the use of farmyard manure in agriculture and the rational use of chemical fertilizers and pesticides.
(4) Centralized treatment of domestic sewage before discharge.
Unit IV The Mystery of the Composition of Matter
Subject 1 The Composition of Atoms
1. The Composition of Atoms
Proton: each proton carries 1 unit positive charge.
Neutron: uncharged
Atom: each electron has a negative charge of 1 unit
(1) The number of charges carried by the nucleus of an atom is known as the number of nuclear charges, due to the amount of charge carried by the nucleus of an atom and the amount of electrons outside the nucleus is equal, but the electrical nature of the opposite, so the atomic electrical nature. Nuclear charge = = Extranuclear
(2) The number of protons in the nucleus of an atom is not necessarily equal to the number of neutrons, and the ordinary hydrogen atom has no neutrons in its nucleus.
(3) The type of atom is determined by the nuclear ( ).
(4) The nucleus occupies only a very small part of the volume of the atom, and there is a relatively large space within the atom in which electrons move at high speeds.
2. Relative atomic mass
(1) to a carbon atom (containing 6 protons and 6 neutrons of carbon atoms) of the mass of 1/12 (about 1.66 × 10-27kg) as a standard, the mass of other atoms and it compared to the ratio of the results, is the relative atomic mass of the atom (symbolized by Ar).
(2) Relative atomic mass is a ratio, and the unit in the SI system of units is " " (generally not written out). The mass of an atom is the absolute mass of the atom in grams or kilograms.
3) The mass of an electron is very small, equal to only 1/1836 of the mass of a proton or neutron, so the mass of an atom is concentrated in the nucleus. The relative mass of each proton and neutron is approximately equal to 1, so relative atomic mass ≈ number of protons + number of neutrons.
Subject 2 Elements
1. Elements.
Element is the general term for.
(1) Types of elements: more than 100 (thus making up more than 30 million kinds of substances)
(2) The top four elements in the earth's crust (mass fraction):
(3) The top four elements in the cells of living organisms:
2. Elemental symbols.
A specific chemical symbol used internationally and uniformly to represent an element.
Significance: ① represents an element; ② represents an atom of this element.
Example: N means: and .
If the coefficient is added in front of the element symbol, it only indicates the number of atoms of the element, not the element. For example, H can indicate both hydrogen and an oxygen atom, while 2H can only indicate; 3Fe indicates; if you want to indicate five magnesium atoms can be recorded as: , seven chlorine atoms can be recorded as: .
Comparison of elements and atoms
Element Atom
Difference is a macro concept, only indicates the type, does not indicate the number is a microscopic concept, both indicates the type, indicates the number
Scope of application Indicates the macroscopic composition of the substance, such as water is made up of the element of hydrogen and the element of oxygen Indicates the microscopic composition of the substance. For example, 1 water molecule is composed of 2 hydrogen atoms and 1 oxygen atom
Contact Element is the general term for a class of atoms with the same nuclear charge Atoms are the smallest particles of the elements
(2) Writing: ① the symbols of the elements indicated by a letter should be capitalized; ① the symbols of the elements indicated by two letters, the first letter should be capitalized and the second letter should be lowercase. For example: calcium, sodium, cobalt magnesium, aluminum and so on.
(3) the characteristics of the Chinese name of the element: metal elements except "mercury" are "gold", for example:
non-metallic elements according to the state of existence of the monomers in the usual circumstances, respectively, add ", "stone", "stone", "stone", "stone", "stone", "stone", "stone", "stone", "stone", "stone", "stone", "stone", "stone" and "stone". stone", "gas", "water" and so on, so we can determine from their side of the elements belong to which category.
3. Periodic Table of Elements.
According to the atomic structure and properties of the elements, the now known more than a hundred kinds of elements according to the atomic number (nuclear charge) arranged in a scientific order, so that the table called the periodic table.
(1) The structure of the periodic table:
1) each - grid: in the periodic table, each element occupies a grid. For each cell, including atomic number, element symbol, element name, relative atomic mass and so on. In addition, the periodic table, but also with different colors of the metal elements, non-metallic elements to do the distinction.
② each row (i.e.: ): each row of the periodic table is called - a period. ***There are one row and one period.
③Each - vertical row (i.e. ): of the 18 vertical rows of the periodic table, except for the 8th, 9th, 10th three vertical rows *** with the formation of a family, the remaining 15 vertical rows, each vertical row is called a family, *** there are 16 families.
(2) The significance of the periodic table: an important tool for the study and research of chemistry
①Provides a theoretical basis for the search for new elements.
② Because the closer the position in the periodic table, the more similar the nature of the elements, can inspire people to look for new substances in a certain area of the periodic table of the elements needed, (such as pesticides, catalysts, semiconductor materials, etc.).