A. Multiple-choice questions (***10 questions, 1 point each, 10 points)
1. (2009? Huangshi) The following phenomenon is a chemical change ( )
A. Paper burning B. Alcohol evaporating
C. Glass breaking D. Ice and snow melting
2. p>2、（2008?Changchun）Crisp cookies exposed in the air for a period of time will become soft, this is because the air contains ( ）
A, oxygen B, nitrogen
C, carbon dioxide D, water vapor
3、（2008?Changchun）In the following glass instruments, you can be directly heated on the flame of the alcohol lamp ( ）
A, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, C, C, D, C, D, D, D, C, D, D, D, D, D, D.
C, D,
4, (2008? Changchun) the following substances can be seen when burning in oxygen, thick white smoke is ( )
A, hydrogen B, sulfur powder
C, red phosphorus D, charcoal
5, (2008? Changchun) the following about iodized table salt (containing KIO3), the correct statement is ( )
A, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K, K. p>
A, KIO3 belongs to the oxide B, KIO3 iodine in the valence of +2
C, iodized salt iodine refers to iodine monomers D, iodized salt can prevent goiter
6, (2008? Changchun) the following about water molecules, the wrong ( )
A, water molecules speed up the movement of water when it is heated B, water into steam when the Water molecules become more spaced out
C, water electrolysis water molecules change D, water consists of two hydrogen atoms and an oxygen atom
7, (2008? Changchun) commonly used "fire bomb" containing liquid carbon tetrachloride, when used, liquid carbon tetrachloride quickly converted to gaseous and covered in the flame. It is assumed that carbon tetrachloride may not have the nature of ( )
A, does not support combustion B, easy to burn
C, gaseous density than air D, easy to vaporize
8, (2008? Changchun) the following about the metal of the statement, the correct is ( )
A, basketball hoops, the surface of the paint, mainly for the sake of aesthetics B, recycling of metals, beverage cans, just to reduce environmental pollution, the recycling of metal, the recycling of metal, the recycling of metal, the recycling of metal, the recycling of metal, the recycling of metal, the recycling of metal, the recycling of metal and the recycling of metal. B, recycling metal beverage cans, just to reduce environmental pollution
C, silver conductivity than actinium good, so commonly used silver as wire without copper D, stainless steel corrosion resistance, commonly used in the production of medical equipment, cookware, etc.
9, (2008? Changchun) the use of knowledge of chemistry, you can tend to avoid harm. The following statements are wrong ( )
A, the rational use of fertilizers and pesticides is conducive to the protection of water resources B, the use of coal-fired desulfurization technology to reduce the production of acid rain
C, gas leaks sprinkled indoors to avoid carbon monoxide poisoning D, to limit the use of plastic bags to help reduce the "white pollution"
10, (2008? Changchun) the following program is reasonable ( )
A, the preparation of NaOH solution: saturated Na2CO3 solution mixed with the appropriate amount of lime water and then filtered
B, the test of carbonate ions: to be tested by mixing with dilute hydrochloric acid, and observe whether to produce bubbles
C, the identification of H2, CH4, CO three kinds of gas: respectively, the burning wood will be used as the basis for the test. gas: respectively, the burning wooden stick into the gas cylinder, observe the phenomenon
D, verify the law of conservation of mass: NH4Cl solution and NaOH solution, compare the total mass of the solution before and after the reaction
Two, fill in the blanks (***11 questions, 36 points)
11, (2008? Changchun) please answer:
(1) in the O, O2, 02-, the oxygen ions;
(2) the chemical formula of nitrogen is;
(3) the figure is the structure of the chlorine atom, which can be seen, the chlorine atom in the chemical reaction is easy to electron (fill in "gain" or "loss"). "lost").
12, (2008? Changchun) chemistry and production and life are closely related. Please answer:
(1) Activated carbon is used to remove the odor of the refrigerator. Is the use of activated carbon sex;
(2) the use of CO sex, can be hematite (the main component is Fe2O3) in the iron smelting out.
13, (2008? Changchun) according to the solubility curve of potassium nitrate shown in the figure:
(1) at 60 ℃, 100g of water, the most dissolved potassium nitrate mass of g;
(2) in the same mass of water, as much as possible to dissolve the potassium nitrate, should be used (fill in "hot water" or "cold water"). "or cold water").
14, (2008? Changchun) in the planting of vegetables in the greenhouse, burning straw is to use the generated CO2 and wood ash (the main component is K2CO3). Please answer
(1) CO2 can promote the role of plants, thereby increasing the yield of vegetables;
(2) wood ash used as fertilizer. Its role and (fill in "nitrogen fertilizer" or "phosphate fertilizer" or "potash fertilizer") comparable;
(3) according to the products of combustion, it can be inferred that the straw must contain potassium and (4) The straw must contain potassium and potash.
15, (2008? Changchun) according to the order of activity of common metals to answer:
(1) in the humid air iron is easy to rust and gold can not be, this is because
;
(2) in magnesium, copper, zinc, three metals. Can not occur with dilute sulfuric acid replacement reaction is;
(3) to compare the activity of copper and silver, if the choice of copper, but also need to choose a salt solution is 16, (2008? Changchun) "the composition and structure of substances determine the nature of substances, nature determines the use, the use of the nature of the embodiment of the nature." According to this theory to answer the following questions:
(1) because alcohol can be burned in the air, so alcohol can be used as;
(2) written or drawn with ink can be preserved for a long time without fading, a fact that reflects the chemical properties of carbon at room temperature;
(3) due to the CO molecules and CO2 molecules of the different, resulting in their chemical properties. different.
17, (2008? Changchun) according to the knowledge of acids, bases and salts, please answer the following questions:
(1) agriculture is commonly used in the improvement of acidic soil of a base is ,
(2) gastric juice contains the right amount of hydrochloric acid. Due to stomach pain caused by excessive stomach acid, the town takes drugs containing Mg (OH) 2 to neutralize the excessive stomach acid, the chemical equation of the reaction is ,
(3) When using water to identify the three homogeneous substances of NaOH, NaCl, CaCO3, the phenomenon based on which the NaOH solid can be identified is .
(4) to investigate whether a chemical reaction can occur between dilute hydrochloric acid, Na2CO3 solution, Ca (OH) 2 solution, all the waste liquid poured into the same clean beaker. In addition to the indicator, the final beaker must contain a solute is ．
Exam point: the properties and uses of common bases; dissolution of heat absorption or exothermic phenomenon; the chemical properties of acids; compound decomposition reaction conditions and substance.
18, (2008? Changchun) a group in the laboratory in the production of CO2, used the following device, please answer the relevant questions:
(1) can be used to collect CO2 device B, because the density of CO2 than the air ,
(2) with the B device to collect CO2, the test to determine whether the collection of the full method is to be placed in the burning wooden bar ;
(3) will be produced to collect the CO2, and then the CO2 is collected. p>(3) the generated CO2 into the litmus test solution, the test solution turned red, the reason is that CO2 and the reaction of carbonic acid;
(4) A device into C device, by pulling the copper wire can control the bottom of the small test tube broken lift. The main purpose of this improvement is (fill in the number);
A. to make the reaction happen or stop at any time B. to make use of the broken test tube C. to produce more CO2
(5) If device A is used to produce oxygen in the laboratory, the chemical equation of the reaction is ．
19, (2008? Changchun) please answer the following questions related to the purification of substances:
(1) the following two programs can remove a small amount of copper oxide in the copper powder
① with dilute hydrochloric acid to remove the copper oxide; ② with the CO reduction of copper oxide.
From the environmental protection and operational simplicity and other considerations, the better program is (① or ②);
(2) to remove a small amount of KOH in K2SO4 solution, you can not choose to use dilute hydrochloric acid, the reason is that it will produce a small amount of KOH. (fill in the name or chemical formula of the specific substance), and the introduction of new impurities.
(3) to make a small amount of NaCl solution Na2SO4 into a precipitate and removed, you can use the appropriate amount of
(4) to remove a small amount of water vapor and hydrogen chloride gas in the hydrogen gas, the gas mixture through a sufficient amount of concentrated sulfuric acid and then through a sufficient amount of sodium hydroxide solution, the hydrogen gas still contains the impurity of ．
Examination points: the investigation of substance removal or purification; common gas test and removal methods.
Topics: combining the information of textbook knowledge.
Analysis: can be based on the nature of the substance aspects of analysis, judgment, so as to draw the correct conclusion. For example, carbon monoxide is poisonous and can pollute the environment.
Comments: the answer to this question to fully understand the nature of various substances, only understand the nature of substances in order to make a correct judgment on the problem.
20, (2008? Changchun) do sulfur combustion in oxygen experiment, put a small amount of water in the cylinder to absorb SO2, after the experiment, the cylinder still remains a certain amount of SO2. around how to deal with the problem of these SO2, students carried out related investigations.
Posing a question
SO2 is the main substance that forms acid rain. What would be the effect of using an alkaline solution such as sodium hydroxide to absorb SO2?
Design and Experiment
Two identical devices were used to do a comparison experiment (SO2 is not soluble in vegetable oil and does not react with it), as shown in the following diagram:
(1) To ensure the accuracy of the experiment, the device should be checked first;
(2) The experiment began to call, the first spring clamps to tighten the latex tubing, and then injected into a syringe filled with SO2 solution, water and NaOH in equal volumes. solution were injected into the gas cylinder filled with SO2;
(3) After the full absorption of SO2, open the spring clamp and observe the volume of vegetable oil into the two gas cylinders after the experiment.
Conclusions and explanations
(1) A experiment, SO2 dissolves in water and reacts with water to form H2SO3, the chemical equation of the reaction is , which can be used to determine the acidity or alkalinity of the solution;
(2) B experiment, SO2 reacts with NaoH to form NaHSO3;
(3) Analyzing the experimental phenomena, we know that the alkaline solution absorbs SO2 more than water. solution is more effective than using water to absorb SO2 ．
Expansion and migration
(1) industry commonly used ammonia to absorb SO2, the (NH4)2SO3 can be used as fertilizer, but in the laboratory to absorb SO2, generally choose NaOH solution rather than ammonia, mainly to consider the nature of;
(2) in the case of coal must be used as fuel. To reduce the emission of SO2, please put forward a rationalization proposal:
,
Examination points: the production, harm and prevention of acid rain; the acidity and alkalinity of the solution determination; writing chemical equations, text expressions, ionization equation.
Topics: combining information from textbook knowledge.
Analysis: the experimental process there is a gas to participate in the device should be tested for airtightness; according to the reactants and products and their law of conservation of mass can be written chemical equations; PH paper can be used to determine the acidity or alkalinity of the solution; alkaline solution is easy to react with sulfur dioxide.
Comments: to answer this question to master the writing of chemical equations and the properties of various substances in the knowledge, only then can the relevant aspects of the problem to make a correct judgment.
21, (2008? Changchun) to prepare a solute mass fraction of 16% of sodium chloride solution of 50g, the need for the mass of sodium chloride g.
Exam point: about the solute mass fraction of simple calculations; a certain solute mass fraction of the preparation of the solution.
Topic: composition of solutions and calculation of solute mass fraction.
Analysis: According to the mass of the solute in the solution = mass of the solution × mass fraction of the solute in the solution, the mass of the solution and the mass fraction of the solute to calculate the mass of the solid solute sodium chloride needed to prepare sodium chloride solution.
Comments: according to the solution of solute mass fraction =, if any two values are known can be calculated the third amount.
Three, answer the question (***1 questions, 4 points)
22, (2008? Changchun) CaCO3 decomposition at high temperatures to produce CaO and CO2, high temperature decomposition of 200g CaCO3 to produce CaO mass.
Topics: calculations based on chemical reaction equations.
Topic: calculations related to chemical equations.
Analysis: According to the decomposition of CaCO3 at high temperatures to produce CaO and CO2, write the chemical equation, the mass ratio between the substances, listed in the proportional equation, you can calculate the mass of CaO generated.
Comments: This question is mainly to test the ability of students to use chemical equations for calculation.
I'll send a copy of the 2008 Jilin provincial exam paper you compare look
A, multiple choice questions (***8 questions, 1 point per question, 8 points)
1, (2008? Jilin) the following chart is conducive to the protection of the environment is ( ）
A, B,
C, D,
Examination points The production, harm and prevention of acid rain; the use of common fuels and their impact on the environment; white pollution and its prevention; the importance of the rational use of chemical fertilizers and pesticides in protecting the environment.
Analysis: our production, life and the environment are closely related to the protection of the environment, we must start from me, can not pile up plastic garbage, less than one day a month to drive a car; agricultural pesticides do not flow into the river; industry, desulfurization of coal-fired treatment.
Comments: Burning sulfur-containing coal will produce carbon dioxide toxic gases, not only pollute the atmosphere, but also the formation of acid rain, polluting the surrounding environment.
2, (2008? Jilin) we live and learn often come into contact with the following substances can be seen as pure ()
A, air B, marble
C, tap water D, 24k gold jewelry
Exam point: pure substances and mixtures of the discrimination.
Topic: combining information from textbook knowledge.
Analysis: air, marble, tap water and other substances are composed of a variety of substances, belonging to the mixture; 24k gold jewelry is composed of a substance, belonging to the pure substance.
Comments: to answer this question to analyze the substance is composed of several substances, if only one substance is composed of pure matter.
3, (2008? Jilin) Wenchuan earthquake, the whole country for the disaster area went in a large number of cabbages, carrots, oil lei and other vegetables, these substances can be directly for the human body to supplement the nutrients are ( )
A, fat B, vitamins
C, protein D, sugar
Exam point: life activities and the six nutrients.
Topic: combining information from textbook knowledge.
Analysis: the nutrients humans need are sugars, fats, proteins, vitamins, water and inorganic salts.
Comments: to answer this question to grasp the types of nutrients in a variety of foods, only then can make a correct judgment on the relevant aspects of the problem.
4, (2008? Jilin) October 24, 2007, "Chang'e I" satellite launch success. Eight hours before the launch to the launch vehicle refueling liquid oxygen and liquid hydrogen. The liquid oxygen is ( )
A, accelerant B, fuel
C, coolant D, catalyst
Exam point: the use of oxygen.
Topic: textbook knowledge similar information.
Analysis: oxygen is a chemically active gas, room temperature can react with many substances, the main use is to support combustion and maintain respiration. Oxygen in the cooling and pressurization conditions into a light blue liquid, called liquid oxygen.
Comments: some students often need oxygen to burn oxygen and oxygen is wrongly regarded as a fuel, oxygen is not flammable, can not be used as a fuel.
5, (2008? Jilin) the following facts do not reflect the nature of particles ()
A, B,
C, D,
Points: particles point of view and the application of model diagrams.
Topic: life situation type.
Analysis: microscopic particles are characterized by: small mass and volume; gaps between particles; all are in constant motion.
Comments: This question is mainly about the characteristics of microscopic particles.
6, (2008? Jilin) sodium chloride is an important chemical raw material. The following statements are incorrect ( ）
A, sodium chloride is commonly known as table salt B, sodium chloride in the sodium element of the valence of +l price
C, sodium chloride can react with potassium nitrate D, saline is 0.9% sodium chloride solution
Exam point: sodium chloride and crude salt purification; calculation of the valence of the elements concerned.
Topic: combining information from textbook knowledge.
Analysis: A, sodium chloride is a commonly used salt substances, life commonly known as table salt;
B, the essence of the valence is the nature of the element's atoms in the atom with other elements when the loss of electrons in the combination of atoms;
C, the reaction that occurs between the salts are complex decomposition reactions, complex decomposition reactions need to meet the generation of precipitate, gas or water to occur;
D, the content of sodium chloride in the fluid inside the cells of the human body is 0.9%, therefore, the 0.9% salt solution is called saline.
Comments: the conditions for the occurrence of the decomposition reaction: the product of gas, precipitate or water, one of the three must have, the decomposition reaction can occur.
7, (2008? Jilin) on the following experiments in the abnormal phenomenon analysis is reasonable ()
A, the production of CO2 gas, always collect CO2 - CO2 collection cylinder is not tightly capped
B, the ignition of hydrogen, an explosion - may not have been checked the purity of hydrogen before ignition
C, a fine wire burning in oxygen, the bottom of the cylinder
C, fine wire in oxygen Burning in oxygen, the bottom of the cylinder exploded - due to the ignition of the match is too long
D, to verify the oxygen content of the air, into the cylinder of water less than 21% - red phosphorus is too much
Examination: hydrogen, carbon monoxide, methane and other combustible gases such as purity testing; experimental data processing or error analysis of the investigation; determination of the composition of the air; the chemical properties of oxygen; the production of carbon dioxide Procedures and points to note.
Topics: experimental operation type; experimental program evaluation questions.
Analysis: A, the density of carbon dioxide is greater than air, the collection of the catheter into the bottom of the cylinder, to take the upward exhaust method of collection, the collection of carbon dioxide will not affect the collection of the cylinder is not tightly closed;
B, hydrogen has a flammable, flammable gas mixed with air may explode when ignited, so be sure to test the purity of the gas before ignition of flammable gases;
C, iron, iron, iron, iron, iron, iron, iron and steel, iron and steel, iron and steel. p>
C, iron wire combustion releases a lot of heat, after the reaction of the high temperature products if directly splashed on the bottom of the gas cylinder, the bottom of the bottle will explode; and ignition of the match is too long may result in the wire can not be burned;
D, verification of the amount of oxygen in the air, in order to make the oxygen reaction is complete, you need to add an excess of red phosphorus; and into the amount of water less than that may be due to the amount of red phosphorus is not enough to cause.
Comments: the analysis of abnormal experimental phenomena: the collection of information related to this, make assumptions about the causes of abnormal phenomena, based on the assumptions of the design of experiments, and finally experimental verification.
8, (2008? Jilin) to distinguish between the following substances is incorrect ( )
A, with slaked lime to distinguish between ammonium chloride and potassium chloride B, with water to distinguish between ammonium nitrate and sucrose solids
C, with barium carbonate to distinguish between dilute hydrochloric acid and sodium sulfate solution D, with zinc sulfate solution to distinguish between brass (Cu, Zn) and gold
Exam point: the salt of the Chemical properties; order of activity of metals and its application; identification of substances, inference.
Topic: identification of substances questions.
Analysis: to carry out the identification of substances, according to the differences in the nature of substances, ammonium nitrogen fertilizer mixed with alkaline substances will produce an irritating odor of ammonia, ammonium nitrate will absorb heat when dissolved in water, carbonate acid gas, in the order of the activity of the metals, the position of the metal in the front of the metal can be located after the metal can be replaced from its solution.
Comments: This question examines the identification of common substances, to complete this question, can be based on the differences in the nature of substances, the requirement of a clear difference in phenomena.
Two, fill in the blanks (***4 questions, 1 point per blank, 12 points)
9, (2008? Jilin) carbon and carbon compounds are the largest family in the chemical world. In the process of learning chemistry we have met many members of the carbon family. Please press the following requirements. Fill in the chemical formula of the substance containing carbon.
Points: the writing and meaning of chemical formulas; the concept of oxides, acids, bases and salts.
Topic: elements and compounds.
Analysis: carbon and carbon compounds are the largest family in the chemical world, in the process of learning chemistry we have met many members of the carbon family: in all kinds of substances in many substances contain carbon, ① carbon monomers; ② oxides containing carbon; ③ salts containing carbon, such as carbonates, bicarbonates, etc.; ④ all organic molecules also contain carbon atoms; ⑤ mixture: coal, oil, natural gas also contain carbon atoms. All organic molecules also contain carbon atoms; ⑤ mixtures: coal, petroleum, and natural gas also contain carbon.
Comments: This question is mainly to test students' ability to write and understand chemical terms, the title design contains both the meaning of the chemical symbols, but also to test the students of the chemical symbols of writing.
10, (2008? Jilin) we have to learn to use. Please fill in the "urea, stainless steel, synthetic rubber, vinegar" into the following appropriate position.
(1) used to make knives ．
(2) It is used as a kitchen condiment.
(3) It is used as a fertilizer for crops.
(4) Used in the manufacture of automobile tires.
Examination points: pig iron and steel; common types of fertilizers and role; synthetic rubber and its application.
Topics: properties and uses of substances; combining information from textbook knowledge.
Analysis: the structure of a substance determines the nature of the substance, the nature of the substance determines the uses of the substance.
Comments: to answer this question to master the knowledge of the nature of various substances, only master the nature of substances to determine the use of substances.
11, (2008? Jilin) known as potassium nitrate solubility increases with temperature. Please fill in the unsaturated solution of potassium nitrate and saturated solution of potassium nitrate in parentheses. (Each process to write a method can)
Examination point: saturated and unsaturated solutions and the method of mutual transformation; solid solubility factors.
Topics: experimental short answer questions; experimental design questions.
Analysis: a saturated solution is a solution that can no longer continue to dissolve a solute under the same conditions; and an unsaturated solution is a solution that can continue to dissolve the solute under the same conditions; therefore, adding a solute or evaporating the solvent to a solution that is close to saturation can make the solution into a saturated solution;
Substance solubility is affected by the temperature; therefore, it can also be taken to Changing the temperature of the solution to make a nearly saturated solution into a saturated solution. The solubility of most solid solutes increases with increasing temperature, so most solid solutes can be taken for the unsaturated solution of the method of cooling to make it into a saturated solution.
Comments: unsaturated solution into a saturated solution generally take three methods: increase the solute, constant temperature evaporation of solvents, change the temperature; change the temperature is generally taken to reduce the temperature; and the solubility of some substances with the temperature increases and decreases, it is necessary to take the method of increasing the temperature.
12, (2008? Jilin) there are many chemicals in the laboratory need to be sealed and preserved, please complete the following table according to the requirements.
The point: chemical properties and physical properties of the difference and application.
Topic: properties and uses of substances.
Analysis: Hydrochloric acid, alcohol, acetic acid and ammonia are volatile, concentrated sulfuric acid is absorbent, and sodium hydroxide, calcium hydroxide, calcium oxide, and white phosphorus can all react with something in the air.
Comments: the key to answering this question is to master the nature of various substances, only then can make a correct judgment on the preservation of substances.
Three, answer the question (***6 questions, 30 points)
13, (2008? Jilin) the teacher in the laboratory to the students to do a demonstration experiment on the nature of oxygen.
(1) Write the chemical equation for the combustion of sulfur in oxygen ．
(2) If the sulfur is still burning when the burning spoon is taken out of the experiment, do you think it should be ( )
A. continued to burn in air B. put into water immediately
The purpose of doing so is ．
Examination points: the phenomenon of the reaction between oxygen and carbon, phosphorus, sulfur, iron and other substances; writing chemical equations, written expressions, ionization equations.
Topic: combining information from textbook knowledge.
analysis: according to the reactants and products and their law of conservation of mass can be correctly written chemical equations; sulfur combustion produces sulfur dioxide gas is poisonous, able to pollute the environment.
Comments: Answer this question to master the writing of chemical equations and sulfur combustion products of the nature, only then can the relevant aspects of the problem to make the correct judgment.
14, (2008? Jilin) according to the given atomic structure diagram, answer the following questions:
Mg and Ca chemical properties (fill in "active" or "inactive");
He's chemical properties (fill in "active" or "inactive");
From this we can see that. When the number of electrons in the outermost layer is the same, the chemical properties are (填寫 "一定 "或 "不一定")相似.
Points: atomic structure schematic and ionic structure schematic.
Topics: microscopic particle simulation diagram type; labeling diagram type.
Analysis: according to the characteristics of the atomic structure schematic: rare gas elements, the atomic outermost electron number of 8 (helium is 2 ); metal elements, the number of electrons in the outermost layer is generally less than 4; non-metallic elements, the number of electrons in the outermost layer is generally more than 4; according to the general view of the outermost layer of the structure of the 8 among them (the outermost is the first layer of the first electron layer of the structure of the 2 electrons) is a stable structure, to answer the question.
Comment: This question tests the students' understanding and mastery of the characteristics of the atomic structure schematic knowledge.
15, (2008? Jilin) charcoal combustion can produce carbon monoxide and carbon dioxide.
(1) Charcoal and carbon monoxide are two different substances. But their chemical properties have many similarities, for example
such as: they can react with, write the chemical equation of the reaction between charcoal and it.
(2) Carbon monoxide and carbon dioxide have different chemical properties because of their different molecular compositions. Write a chemical equation to distinguish them. (Write one can)
Examination points: the chemical properties of carbon; the chemical properties of carbon dioxide; the chemical properties of carbon monoxide; writing chemical equations, word expressions, ionization equations.
Topic: properties and uses of substances.
Analysis: charcoal and carbon monoxide can both react with oxygen, charcoal reacts with oxygen to form carbon dioxide, carbon dioxide cannot react with oxygen. Chemical equations can be written based on reactants and products and their law of conservation of mass.
Comments: the key to answering this question is to master the properties of carbon monoxide, charcoal and carbon dioxide, only then can make a correct judgment on the problem.
16, (2008? Jilin) Rongrong students according to the diagram in the laboratory to prepare oxygen.
(1) Recognize the apparatus: Write the name of the heat source in the figure , and point out a little caution when using it .
(2) Sequence of operations:
①Pharmaceuticals and cotton. If there is no indication of the amount, the amount of solid drug should be ．
②Connect the apparatus and fix the test tube.
③Heating. When heating, you should first ．
(3) experimental analysis: please help her to find out the above experimental process missed an experimental step
Examination points: the preparation of oxygen and attention to the operation of the steps; oxygen preparation device.
Topics: experimental short answer questions; combining information from textbook knowledge.
Analysis: (1) familiar with commonly used experimental apparatus, understand the principle of their use;
(2) if there is no indication of the dosage, the solid drug should be taken only to cover the bottom of the test tube; preheat the test tube before heating;
(3) the device for the preparation of gases should also be checked for gas tightness of the device.
Comment: This question examines the basic experimental operations should pay attention to the problem, seemingly small problems, may affect the entire experiment, so students must pay attention.
17, (2008? Jilin) April 9, 2008, a city of hydrochloric acid leakage. Hydrochloric acid leakage of the moment thick acid fog filled the air with a faint acidic odor ... the leakage of acid flow downhill people in low-lying villages, acid fog led to more than ten people hospitalized for observation. After seeing this news, the school's chemistry activity group held a workshop on accident management. Please use your knowledge of chemistry to participate in it．
Analysis of accident hazards
(1) Hydrochloric acid is corrosive causing environmental pollution.
(2) The irritating odor of hydrochloric acid is dangerous to human health.
Accident treatment program
For the accident treatment, the students launched a lively discussion: (1) Xiaoming proposed to use soluble alkali to deal with, for example: (fill in a specific substance). The reason is
(2) Xiaohong put forward a different opinion? She thinks that in the case of a contaminated area is too large to use an acid-base indicator, it is impossible to determine because ．
(3) As a result of the above discussion, it was decided to use a salt substance to treat the acid. For example: (fill in a specific substance, the advantage of choosing this substance is ．
Reflection on Accident Management
(4) If we still can't determine that the treated soil must be neutral after treating the leaked acid by using the method in (3), we should also take a sample of the treated soil. The soil sample will be used to further determine the neutralization of the soil.
Topics: the chemical properties of acids; acid-base indicators and their properties; neutralization reactions and their applications; determination of the acidity and alkalinity of solutions.
Topic: combining information from textbook knowledge.
Analysis: acids and bases can occur neutralization reaction, carbonate acid can be gassed, the phenomenon is obvious, to determine the acidity or alkalinity of the solution can be used PH test paper.
Comments: This question examines the neutralization of acids and bases, to complete this question, can be based on existing knowledge.
18, (2008? Jilin) iron and steel mills purchased iron oxide (Fe2O3) containing 85% of hematite 1000t. ready to use these iron ore refining pig iron containing impurities 3%.
(1) As shown in the figure. Complete the calculation to find the mass of pure iron.
(2) Calculate the mass of pig iron using the chemical equation. (The reaction principle is 3CO+Fe2O3Fe+3CO2) (The result of the calculation is kept in integer)