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In Math and Science, I can understand the lessons but can't do the problems. I'm not sure why I'm doing this, but I'm not sure if I'm doing it.
In mathematics, science and chemistry, the class listens to understand, but can not do the problem to do. The first time I saw this was when I was a student at the University of California at Berkeley.

Not learning how to apply the knowledge

What is the version of mathematics, science and chemistry in Shanghai high school?

It's the second phase of the curriculum reform that is unique to Shanghai, and now it should still be a test book

Seeking a chemistry master, teach me how to learn organic chemistry Why do I listen to the class, and do a problem with more than half of them will not be able to do why ah.

Practice is too little, I used to be this problem, and then the teacher said to do more questions to line

Why the seven courses of the examination, are based on mathematics, science and chemistry from the point of view of enrollment, mathematics, science and chemistry compared to the liberal arts, more differentiated.

From the perspective of promotion and further development, the college entrance examination is also a majority of science students. If the foundation of mathematics and chemistry in junior high school is not good, it will affect the further study in high school.

Therefore, the policy of each region in the development of the secondary school examination, to the mathematical and physical science is the main.

The first year of high school, you can understand the class and do not get up how to do the problem?

First of all, the basic knowledge to understand and memorize firmly and then appropriate practice. The condition of the students to use the holidays to find a teacher to make up classes. The first thing you need to do is to get your hands on some of the most popular and popular products in the world, and you'll be able to do that in the future. You can apply for a trial half hour, not satisfied with the stop listening to the class without charge. The first thing you need to do is to get your hands on some of the most popular products and services in the world.

Why is it that you can't do anything after class?

Listening to understand and will do things are two different things, but also review after class, more practice

In the handwriting board can do math and science problems

Can ah, our teacher is handwritten on it and then video sent to us as a homework assessment

On the high school a month or two, I failed all the math, science and chemistry, listening to understand, but will not be able to do the problem, how to do. I still have to save it

As long as you listen carefully, do more problems, slowly, surely can

2005 (class reform area) in the recruitment of mathematics, science and chemistry test

Yiyang City, Hunan Province, the 2005 midterm Chemistry test - the new standard

(full marks 100 points, the examination time of 90 minutes)

Relative atomic mass may be used. H-1 C-12N-14 O- 16 S-32 Zn-65 16 S-32 Zn-65

Volume 1

I. Multiple Choice Questions (2 points for each sub-question; ***44 points. Each sub-question only one meets the requirements of the topic)

1. December 26, 2004, the Indian Ocean shocked the world of the tsunami, the tsunami disaster occurred in the following changes belong to the chemical changes ( )

A. trees break B. houses collapsed C. railroad tracks rusted D. road washed out

2. the following substances, belonging to the pure substance ( )

2.

A. Rare gases separated from the air B. Partially frozen distilled water

C. Pig iron obtained after smelting iron ore D. Residue after the reaction of heating potassium permanganate

3. The use of the following substances, the nature of the use of the other three are fundamentally different ( )

A. Hydrogen is used to fill the balloon B. Dry ice is used in artificial rainfall

C. Magnesium powder is used as fireworks and flares D. Copper wire is used as electrical wires

4. The following statements lack scientific basis ( )

A. Metals can be corrosion-resistant B. Desalination of seawater can be desalinated

C. Wastewater can be utilized D. Freshwater can be turned into oil

5. The following is the air pollution index and the quality of the level of the quality of the corresponding relationship:

Air Pollution Index 0--50 51-100 101-200 201--300 >300

Air Quality Condition Excellent Good. Light Pollution Moderate Pollution Heavy Pollution

Air Quality Level I Ⅱ Ⅲ Ⅳ V

On June 3, 2005, the Air Pollution Index (API) of Yiyang City District was 82-93. According to the above information, the air quality level and air quality condition of Yiyang City District on that day were ( )

A. I Excellent B. Ⅱ Good C. Ⅲ Light Pollution D. V Heavy Pollution

6. The Kyoto Protocol came into force on February 16, 2005, and its core connotation is: to reduce emissions of greenhouse gases in order to control global warming. Lead to the greenhouse effect of the main gas is ( )

A. Carbon dioxide B. Oxygen C. Nitrogen D. Hydrogen

7. A mineral water label printed on the main mineral composition and content is as follows (unit mg / L): Ca-20, K ~ 3, Zn a 0.06, F ~ 0.02 and so on. Here Ca, K, Zn, F refers to ( )

A. elements B. atoms C. monomers D. ions

8. burning firewood, usually some of the firewood racks, in order to burn more strongly, this is because ( )

A. heat dissipation speed up the speed of the gathering of heat increases

C. firewood ignition point is reduced D. firewood and the air contact area increases

C. firewood and air contact area is increased. The area of contact between the firewood and the air increases

9. The following chemical equation is true again ( )

A. Iron filings dissolved in dilute sulfuric acid: 2Fe + 3H2SO4 == Fe2(SO4)3 + 3H2↑

B. Table salt dissolved in potassium nitrate solution: NaCl + KNO3 == NaNO3 + KCl

c. Charcoal burns in insufficient oxygen: 2C + O2 2C0

D. Hydrogen peroxide decomposition:

10. firecrackers are easy to personal and environmental hazards, Yiyang City *** has long been in the city issued a ban, as a secondary school students, in addition to taking the lead to comply with the outside, but also to do a good job of publicity and explanation. Prohibition of firecrackers sign is ( )

11. a solute dissolved in water, the formation of the solution compared with water, will not change is ( )

A. boiling point B. conductivity C. color D. the composition of water molecules

12. the following table is an acid-base indicator in the different pH ranges of the color:

Color red, orange, green, blue, purple

pH range 1 to 3. 4 to 5 6 to 7 8 to 10 1 1 to 14

To a small amount of the indicator drops of dilute hydrochloric acid, add sodium hydroxide solution drop by drop, the color change is ( )

A. from red to blue B. from green to orange C. from blue to green D. from violet to red

13. The figure on the right is a fertilizer factory produces a kind of chemical fertilizers The picture on the right shows part of a fertilizer produced by a fertilizer factory, which belongs to ( )

A. Nitrogen fertilizers B. Phosphorus fertilizers C. Potash fertilizers. D.Compound fertilizer

14.Scientists predict that hydrogen will become the main source of energy in the 2l century, but in addition to first solve the problem of energy consumption in the preparation of hydrogen, but also have to solve the problem of

A.Raw materials are limited B.Causing environmental pollution

C.Inconvenience in the storage and transportation of D.Hydrogen combustion of the heat released less

15.YiYang Songhua eggs are famous all over the country and are exported to Southeast Asian countries. The ingredients for its production are soda ash, salt, quicklime, grass ash (containing potassium carbonate), boiling water, and rice bran, rice husk and other accessories. Between the ingredients is first quicklime and water reaction to produce slaked lime, try to deduce that the other most likely chemical reaction is ( )

A. reaction B. decomposition reaction C. complex decomposition reaction D. replacement reaction

16. a laboratory has four medicine cabinets were stored in the following medicines:

medicine cabinets a B C D

medicines zinc, copper, sodium sulphate Sodium hydroxide hydrochloric acid

iron, magnesium sodium carbonate potassium hydroxide dilute sulfuric acid

The laboratory purchased two bottles of anhydrous calcium chloride, it should be placed in the ( )

A. Cabinet A B. Cabinet B C. Cabinet C D. Cabinet D

17. In the following cases, buried in the ground, the fastest corrosion of the cast iron pipeline is ( )

A. In the wet, dense soil B. In dry, dense soil

C. In wet, loose soil D. In dry, loose soil

18. June 5 each year is the World Environment Day, the 2005 World Environment Day in China's theme is: everyone participates in creating a green home. The following practices are not in line with this theme ( )

A. Returning farmland to forests B. Using large quantities of disposable foam plastic tableware

C. Using phosphorus-free detergent D. Banning the use of honeycomb stoves

19. In the absence of acid-base indicator premise, in order to remove a small amount of hydrochloric acid in the calcium chloride solution, to get the pure calcium chloride solution, the most appropriate choice of a reagent is ( )

A. The most suitable choice of a reagent is ( ).

A. silver nitrate solution B. clarified lime water

C. powdered quicklime D. powdered calcium carbonate

20. a lime factory calcined limestone production of quicklime, if the production of l 008 t quicklime, the need for 90% of the calcium carbonate containing limestone quality (relative atomic mass: Ca-40 C-12O-16) ( )

A. 1 620 t B. 1 800 t 620 t B. 1,800 t C. 1,900 t D. 2,000 t

21. According to the solubility curve on the right, the following statements are incorrect ( )

A. t1 ℃, the solubility of substance A is less than the solubility of substance B

B. t2 ℃ C, the saturated solution of substance A and B containing the mass of A and B substances are equal. /p>

c. t3 ℃ of the saturated solution of a, b two substances cooled down to t2 ℃, will precipitate crystals

D. When a small amount of a substance mixed with a substance b, can be used to cool the hot saturated solution of the method of purification of a

22. May 2005, Yiyang City, Ziyang District of the Tiger Hill unearthed a number of Warring States bronze, in fact, as early as in China in the Shang Dynasty to make a Exquisite bronze, to the Warring States period has been able to smelt iron and steel. The chronological order of human development and utilization of the following metal monomers has an intrinsic connection with the strength of metal activity. From this inference, the human development and utilization of the following metals from first to last order is ( )

A. Cu Fe Al Zn B. Cu Zn Fe Al

C. Cu Fe Zn Al D. Al Zn Fe Cu

Volume Ⅱ

Second, fill in the blanks (this question *** 20 points)

23. Write the following Chemical symbols:

(1) three nitrogen molecules (2) two magnesium ions

24. The chemical formula of the compound formed by the most abundant element in the human body and the most abundant metal element in the earth's crust is .

25.Ambicillin is a common anti-inflammatory drugs, its main component ampicillin chemical formula for C16H19N3O4S-3H2O, which contains a kind of elements.

26. Chemistry and human health are closely related. Some important nutrients such as: sugar, starch, oil, protein, vitamins, etc., is important to human life activities. As in the critical period of physical growth and development of secondary school students, can not be partial, picky eating, every day to take in enough, balanced nutrition.

(1) a student usually do not eat, only eat vegetables, the result of weakness, fatigue and even coma and other symptoms, he lacks of nutrients;

(2) a student in the graduation physical examination, check out the protein intake is not enough. If you are a doctor, you would suggest that he should eat more food in his regular diet is (fill in one).

27. Laboratory in the clean-up of experimental drugs, found that two bottles of colorless solution lost label, only know that they are Na2CO3 solution and BaCl2 solution, try two chemical methods to identify them (write the identification of the reagents used in the chemical formula or name can be): (1); (2).

28. Last year, the city of Heshan District, Yuejiaqiao Town, an outbreak of avian influenza, in order to prevent the spread of the epidemic, in addition to rapid isolation, but also the virus infected poultry houses, tools and other disinfection. A disinfectant used in disinfection is potassium permanganate (KMnO4), which belongs to (fill in "oxide" "acid" "alkali" or "salt"), of which potassium permanganate (KMnO4) is the most common. "), in which the valence of manganese is valence.

29. Schools, homes, offices commonly used in the basic principle of the water purifier can be shown in the figure to the right of the simple water purification device. The role of the stones used, fine sand, etc. is to play the role of adsorption.

30. In accordance with the "West-East Gas Pipeline" program, the city of Yiyang City to go in the laying of natural gas pipelines, residents will soon be using natural gas. Natural gas is the most colorless and odorless gas, less dense than air. Natural gas leakage, fire, static electricity is easy to explode, the delivery of natural gas, in which mixed with a strong *** sexual odor of the gas (mercaptan).

(1) The main component of natural gas is CH4, which belongs to (fill in "organic" or "inorganic");

(2) The purpose of mixing sulfuric acid in the natural gas delivered is;

(3) When natural gas leakage occurs indoors, turn off the valve immediately. natural gas leakage, to immediately close the valve, open the windows to ventilate, must not do is (fill in one).

31. A, B, C and D are common compounds, and A contains potassium. The reaction relationship between them is as follows:

① 2A + B== C + 2H2O ② C + D== Ba2SO4↓ + 2A

③ D + CuSO4 === BaSO4↓ + Cu (OH) 2↓

According to the above information, deduce the A, B, two substances, the chemical formula: A, B; Write the reaction ② of the chemical equation: .

32. will be equal to the mass of A, B two pieces of metal, respectively, into the solute mass fraction of the same amount of dilute hydrochloric acid, the generation of hydrogen mass (m) and the reaction time (t) of the relationship between the right figure shows (the product of A, B two elements of the same valence). Analysis of the right figure, you can get the information (any two):

(1)

(2)

Third, short answer (this question *** 10 points)

33. March 29, 2005 evening, Beijing-Shanghai high-speed Jiangsu Huai'an section of two trucks collided with a traffic accident, resulting in liquid chlorine tankers in the (Cl2) a large leakage, causing three townships next to the highway villagers. This caused major casualties among villagers from three townships along the highway. A large amount of yellow-green gas could be seen in the sky and a pungent odor could be smelled at the accident site. Firefighters wearing gas masks and suits, spraying water and lye with high-pressure water cannons into the sky and the chlorine gas settling on the ground as a means of eliminating the pollution and damage caused by Cl2.

(1) Based on the above information, summarize the physical properties of chlorine gas (Cl2):

(2) During the rescue, Ca(OH)2 solution can be sprayed to absorb the chlorine gas. The chemical equation of the reaction is known to be

2Cl2+2Ca(0H)2==X+Ca(ClO)2+2H2O, then the chemical formula of X is .

(3) Tell the villagers who were around the scene a measure to protect themselves.

34. At the end of the examination, you will graduate from junior high school. On the occasion of leaving your alma mater, you want to leave a last good impression, do care for the school grass and trees, do not throw things ...... Suppose you are organizing your own things, cleaned out the following items:

A. Waste workbooks, B. Rotten apples, C. Can bottles, D. Moldy cookies, E. Rusty nails.

(1) you should be put into the "recyclable trash" is (fill in the serial number);

(2) you use hydrochloric acid to remove the rust on the nail (the main ingredient is Fe2O3), in order to reuse, write a chemical equation to remove rust .

(3)Write a sentence to advise other grades to take care of the school environment.

35. Materials science has become one of the hottest frontier subjects in the world today. Materials are generally divided into metal materials, inorganic non-metallic materials, synthetic materials and composite materials, etc. On March 28, 2005, the first prize for national technological invention, which has been vacant for six consecutive years, was awarded to the group led by Huang Boyun, an academician of the Chinese Academy of Engineering and president of the Central South University, for their invention of the "high-performance charcoal/carbon aerospace braking material preparation technology. ". Huang Boyun is Yiyang City, Nanxian people, he and his innovative team after 20 years, more than 7,000 days and nights of struggle, after countless failures, finally succeeded, not only to break the monopoly of Europe and the United States and the technology blockade, and better performance.

(1) "Charcoal, charcoal aerospace brake materials" in the two "charcoal" on behalf of two different carbon-containing materials, which made this aerospace brake material belongs to the material.

(2) The extensive use of synthetic materials has both advantages and disadvantages, please write any one of the advantages and disadvantages. Advantages , disadvantages .

(3) From the deeds of Huang Boyun, for scientific inquiry, what do you think?

Fourth, the experimental questions (this question ****16 points)

36. Through a year of chemistry, you have mastered the laws relating to the laboratory preparation of gases, please combine the following device diagram to answer the question. (Friendly tips: the following selected devices are filled with device code)

(1) Write the name of the designated instrument in the diagram; ①; ②. .

(2) laboratory preparation and collection of CO2 should be connected with two devices, the chemical equation of the reaction is , test the collection of CO2 in the cylinder is full of the method is

(3) laboratory with KMn04 to produce O2, can choose the occurrence of the device is , and at the same time with the E device to collect O2, the experiment stops when the order of operation is .

(4) If device c is used to collect a gas, the gas should have the property of .

37. A school of exploratory learning group found that the copper green [Cu (OH) 2CO3] heat decomposition, in addition to the generation of CO2 and water vapor, there are a number of black powdery solids in the test tube. They investigated experimentally to analyze the composition of the black solid and to verify the gas produced. Please fill in the blanks:

(1) Ask the question: what is the black solid?

(2) Conjecture and hypothesis: the black group may be: a. Charcoal powder b. Copper oxide c. .

(3) Check the information: charcoal powder and copper oxide are black solids, in which charcoal powder does not react with dilute acid and is not soluble in dilute acid, while copper oxide can react with dilute acid and dissolve.

(4) design an experimental program: to the black group in the test tube drop a sufficient amount of (fill in the chemical formula) solution, fully reacted, observe the dissolution of the solid and the color of the resulting solution.

(5> phenomena and conclusions: if the conjecture a is correct, the phenomenon is; if the phenomenon is , then the conjecture b is correct; if the phenomenon is , then the conjecture c is valid.

(6) If the device on the right to verify the two gas generators, should be generated by the gas mixture first through the device, and vice versa, what will be the effect? (6) If the two gas products are verified using the device at right, the gas mixture should be passed through the device first, and what is the effect of doing it the other way around? When the gas is passed into device A for verification, the gas flow should be passed through.

V. Calculation questions (this question *** 10 points)

38. Sudan red is a synthetic red dye. The latest research shows that its metabolites in vivo have strong mutagenicity and carcinogenicity, the country is adding Sudan red food. Known as one of the most common chemical formula of Sudan red C16H12NO, try to calculate:

(1) the relative molecular mass of Sudan red;

(2) Sudan red in the mass ratio of the elements;

(3) Sudan red in the elemental mass fraction of nitrogen.

39. will be a piece of zinc-copper alloy into 74.2 g of dilute H2SO4, just the complete reaction, the generation of hydrogen 0.2 g. Seek:

(1) after the reaction of the solution obtained by the mass fraction of solute;

(2) the laboratory existing 98% of the 20 g of concentrated sulfuric acid, how many grams of water to be formulated into. 19.6% of dilute sulfuric acid?

Yiyang City, Hunan Province Chemistry Answers

1. C 2. B 3. C 4. D 5. B 6. A 7. A 8. D 9. C 10. B 1 1. D

12. A 13. A 14. C 15. C 16. B 17. C 18. B 19. D 20. D

21. B 22. C

23.(1 )3N2 (2)2Mg2+ 24.Al2O3 25.5

26.(1)Sugar (or starch) (2)Fish, meat, eggs, soy products, etc.

27.Phenolphthalein, litmus, dilute hydrochloric acid (HCl), lime water [Ca(OH)2], soda ash solution (Na2C03), etc.

28.Salt +7 29.Filtering activated charcoal

29.

30. (1) organic matter (2) conducive to the timely detection and treatment of leaks (3) turn on the lights, telephone, ignition, undressing, impact or friction of metal, etc.

31. A - KOH B - H2S04 K2SO4 + Ba (OH) 2 = = BaSO4↓ + 2KOH

32. ① B B is more active than A, ② A and B are completely reacted, ③ A gives off more H2 than B, ④ B gives off H2 faster than A, ⑤ B produces more H2 than A at time t1, and ⑥ the relative atomic mass of A is less than the relative atomic mass of B.

33.(1) A yellowish-green, toxic, *** gas that is denser than air and soluble in water (fill in at least two)

(2) CaCl2 (3) Cover your mouth and nose with a wet towel and leave the scene quickly.

34.(1)A,C,E (2)Fe203+6HCl==2FeCl3+3H2O (3)Caring for the environment is everyone's responsibility; care for our **** same home; grass also has life, do not trample.

35.(1)Composite (2)Advantages: lightweight; difficult to corrode; low cost; higher strength; good insulation. Disadvantages: white pollution; harmful to health. (3) Failure is the mother of success; perseverance is victory; to have the spirit of innovation; to carry forward the team spirit; hard work, in order to succeed; to rise to the challenge, the courage to climb the peak of science and technology.

36.(1.)①Long-necked funnel②Sink

(2)BD CaCO3+2HCl==CaCl2+H2O+CO2↑ Stick a burning stick of wood into the mouth of the gas cylinder to see if it goes out quickly. (3)A Move the gas guide tube out of the water before removing the alcohol lamp to stop the heating.

(4) It is less dense than air and does not react with substances in air.

37.(2) A mixture of charcoal powder and copper oxide (4) H2SO4 (HCl, HNO3 are also acceptable) (5) The black solid does not dissolve, and the solution is colorless; the black solid dissolves completely, and the solution is blue; the black solid partially dissolves, and the solution is blue. (6) B interferes with the verification of water vapor in the gas mixturea

38. Solution : (1) Relative molecular mass of sultanas = 12 × 16 + l × 12 + 14 × 2 + 16 = 248

(2) The mass ratio C : H : N : 0 = (12 × 16) : (1 × 12) : (14 × 2) : 16 = 48:3:7:4

( 3) Mass fraction of elemental nitrogen = 11.3%

A: (I) The relative molecular mass of sultanas is 248;

(2) The mass ratio of carbon, hydrogen, nitrogen and oxygen in sultanas is 48:3:7:4;

(3) The mass fraction of elemental nitrogen in sultanas is 11.3%.

39. Solution: (1) Let the mass of Zn in the alloy be x, and the mass of ZnSO4 in the resulting solution be y

x=6.5 g y=16.1 g

Mass fraction of the solute in the resulting ZnSO4 solution = 20%

(2) Let the mass of water required be z, then

20 g × 9.8% = (z+) × 19.6%. 20 g) × 19.6% Z = 80 g

A: (1) The solute mass fraction of the resulting solution is 20%.

(2) 80 g of water is required.

Why did I make the pot rice not work potpourri why ah!

It may be that you put too much water, or the fire is not enough, the key to master the fire, do not fire, so as to avoid the bottom of the paste off, the top of the and not cooked enough Owner, can solve your problem?