Fifth grade second volume science test paper

Midterm test paper (A) (exam time 90 minutes)

Class student number and name score

Relative atomic mass used in this paper: C 12; O 16; Fe 56; S 32; H 1; N 14

1. Multiple choice questions (2 points for each question, ***40 points)

1. It is understood that approximately Every 1,000 kilograms of scrap mobile phones can extract 200 grams of gold, while gold mines of the same quality can only extract 10 to 15 grams of gold. The element symbol of gold is ( )

A Ag B Ar C Au D Sn

2. In the following box, the schematic diagram that conforms to the meaning of 2N2 is ( )

3. The particles that can maintain the chemical properties of hydrogen are ( )

A hydrogen element B hydrogen atom C hydrogen molecule D hydrogen ion

4. The essential difference between molecules and atoms is ( )

A Molecules are large, while atoms are small

B Molecules are particles that make up matter, but atoms are not

C Molecules can maintain the chemical properties of matter, while Atoms cannot

D In chemical reactions, molecules can be divided, but atoms cannot be divided

5. The conclusions that cannot be drawn from alpha particle scattering experiments are ( ) < /p>

A Most of the atom is empty B All the positive charge in the atom is concentrated on the nucleus

C There are neutrons in the C atom D Almost all the mass of the atom is concentrated on the nucleus< /p>

6. The American Iridium Corporation (now bankrupt) originally planned to launch 77 satellites to achieve global satellite communications. The number of satellites it planned to launch was exactly equal to the number of electrons outside the atomic nucleus of the iridium element. Which of the following statements about the iridium element is correct ( )

A The nuclear charge of the iridium atom is 77 B The relative atomic mass of the iridium atom is 77

C The iridium atom's The number of protons is 70 D. The iridium element is a non-metal element

7. Among the following groups of substances, the elements composed of the same element are ( )

A Diamond, graphite, C60 B Oxygen, hydrogen, nitrogen

C Coal, petroleum, natural gas D Water, ice, dry ice

8. Since the implementation of my country's "Road Traffic Safety Law" on May 1, 2004, The traffic control department has further strengthened the monitoring and punishment of drivers who drive under the influence of alcohol. Traffic police often have instruments equipped with potassium dichromate to detect whether drivers are driving under the influence, because ethanol molecules can turn the orange-red potassium dichromate into green chromium sulfate.

In potassium dichromate (K2Cr2O7) and chromium sulfate [Cr2(SO4)2], the valence of chromium element is ( )

A +3, +6 B +6, +3 C +3, +5 D +5, +3

9. On a sunny day, green plants usually absorb about 5 grams of carbon dioxide per square meter per day for photosynthesis. One month (based on 30 days) per square meter The mass of carbon contained in the carbon dioxide absorbed by the leaves is approximately ( )

A 41 grams B 61 grams C 151 grams D 181 grams

10. Among the following compounds, the mass fraction of iron The smallest is ( )

A FeO B Fe2O3 C Fe3O4 D FeS

11. The incorrect description of the chemical properties of oxygen is ( )

A. has Oxidizing B. Reactive chemical properties

C. Combustible D. Combustible and can support combustion

12. Among the following judgments about the reaction of substances with oxygen, which one is wrong? is ( )

A. It must be a combination reaction B. It must be an oxidation reaction

C. It may be a combination reaction or it may be an oxidation reaction D. It may not be a combination reaction, but It must be an oxidation reaction

13. The following items: ①Type of atom ②Number of molecules ③Type of element ④Type of substance ⑤Atomic mass, there must be no change before and after the chemical reaction ( )

< p>A.②③ B.②③④ C.①③⑤ D.①④③

14. As a green energy source, the chemical equation of combustion is X+ 2O2 CO2+2H2O. According to the law of conservation of mass, determine the The molecular formula is ( )

A.H2 B.CH4 C. D.

15. What is not directly related to the carbon cycle in nature is: ( )

A. Photosynthesis b. Respiration C. Microbial decomposition D. Transpiration

16. Among the following chemical equations, the correct one is ( ) A.2H202==2H2O2↑ B. 4P+5O2 2P2O5

C. Ca(OH)2 +CO2===CaCO3↓+H2O D.NaOH+CuSO4==Na2SO4+Cu(OH)2

17. During the SARS period, most public places such as hotels and shopping malls used Ozone machine disinfects. What we have learned is that the ozone layer has a protective effect on organisms on the earth because it can: ()

A. Block and weaken excessive ultraviolet rays.

C. Enhance the photosynthesis of plants D. Transmit more ultraviolet light

18. The following operations are related to both the physical properties of carbon dioxide and the chemical properties of carbon dioxide: )

A. Use carbon dioxide to make dry ice B. Dissolve carbon dioxide under pressure to make soda water

C. Carbon dioxide can harden lime slurry D. Carbon dioxide can be used to extinguish fires

< p>19. The laboratory uses potassium permanganate to heat to produce oxygen. The steps are as follows: ① Heating; ② Check the air tightness of the device; ③ Fill the medicine; ④ Use the drainage method to collect oxygen; ⑤ Take out the conduit from the water tank; ⑥Turn off the alcohol lamp; ⑦Connect the device in the correct order.

A. ⑦②①④⑥ B. ⑦③①②④⑥⑤

20. Which of the following statements about plant respiration and photosynthesis is correct ( )

A. All biological cells perform photosynthesis B. Photosynthesis occurs during the day and respiration occurs at night

C. All biological cells perform respiration D. Plant respiration absorbs carbon dioxide and releases oxygen

2. Fill in the blanks (25, 27, 28, 29, 30, 31 ( 2) 2 points for each grid, 1 point for each other grid, ***40 points)

21. The development of science and technology in the 20th century has provided people with the possibility of observing and manipulating individual atoms and molecules. , thus realizing the direct use of atoms to create molecules.

Glucose is one of the important nutrients needed by the human body. Its chemical formula is C6H12O6. If the above method is used to produce glucose, please indicate the names of the atoms required.

22. We live in the material world, and thousands of substances around us are composed of (fill in "molecules" or "atoms" or "elements"). The water we drink every day is made up of and . Water is the source of life. Each of us should care about water, cherish water, and protect water. Please tell us a specific way to save water based on your own life: .

23. Use chemical symbols to represent:

Sodium ion, phosphorus atom, magnesium element, hydrogen chloride molecule

24. Determine which number "3" represents in the following chemical symbols meaning, and fill in its serial number in the corresponding space.

A Fe3+ B SO3 C Na+3AlO3 D 3NO

① It represents the number of molecules; ② It represents the number of charges carried by an ion;

③ It represents the valence of elements; ④ It represents the number of atoms contained in a molecule.

25. In a compound composed of two elements, A and B, the mass ratio of A and B is 1:16, and the relative atomic mass ratio is 1:32. In this compound, A and B The atomic fraction ratio of is.

26. Air pollution brings harm to humans and nature. Harmful substances emitted into the air can be roughly divided into two categories: gases and gases. From a global perspective, the most gaseous pollutants emitted into the air are , , , nitrogen dioxide, etc.

27. When brushing your teeth with toothpaste containing sodium fluoride (NaF), sodium fluoride reacts with the tooth mineral hydroxyapatite [chemical formula is Ca10 (PO4) 6 (OH) 2] to generate fluorophosphorus. Greystone [Ca10(PO4)6F2]. Fluorapatite is more acid-resistant, thereby achieving the purpose of preventing and treating dental caries. Write the chemical equation of the reaction to generate fluoroapatite

28. There are two plastic soft bottles A and B. Bottle A contains a mixed gas of CO and O2, and bottle B contains CO2 gas. A classmate caught two live locusts from the wild, put them into two plastic soft bottles, and tightened the bottle caps. As a result, both locusts died soon. Please answer according to the options given below. The main cause of death of locusts is:

Bottle A, bottle B.

① No food ② The gas cannot be supplied for breathing ③ The gas is toxic ④ The space for movement is too small

29. Use red phosphorus to burn in a bell jar to measure the oxygen content in the air. What happened? The experimental phenomena are: (1)________; (2)________. If the amount of red phosphorus is insufficient, the measured oxygen volume will ________ (fill in "too large", "too small" or "unchanged").

30. Please use two chemical methods to identify oxygen and carbon dioxide. The method is (1)

(2)

31. A small amount of carbon dioxide in the air is of great significance to the life activities of animals and plants. However, if too much carbon dioxide is emitted, it will Cause the greenhouse effect.

(1) Green plants absorb CO2 through the action of water and release CO2 into the atmosphere through the action of water.

(2) Scientists use "combination conversion" technology to react CO2 and H2 to generate a chemical raw material, ethylene and water. The chemical equation is: 2CO2+6H2=ethylene+4H2O, then the chemical formula of ethylene for.

(3) In order to slow down the increase of CO2 content in the atmosphere, the following suggestions are reasonable. (Fill in the serial number)

① Develop new energy ② Reduce the burning of fossil fuels ③ Plant trees

3. Experimental design and inquiry questions (***20 points)

32. (4 points) Microscopic simulation questions: Answer the following questions through the reaction diagram on the right:

⑴Substance C belongs to pure substances (fill in the substance classification).

⑵Explain the essence of chemical reactions from the perspective of molecules and atoms.

33. (8 points) Nitrogen fertilizer can promote the growth of the stems and leaves of crops and make the leaves dark green. A classmate discovered that the flowers and plants in her flower pots were growing slowly, so she applied a nitrogen fertilizer. The picture on the right is part of the text on the nitrogen fertilizer packaging label.

Try to calculate based on relevant information:

⑴ How many elements does this nitrogen fertilizer contain?

⑵What is the relative molecular mass of ammonium bicarbonate?

⑶What is the purity of this nitrogen fertilizer (that is, the mass fraction of ammonium bicarbonate in the fertilizer)?

34. (8 points) The students in the chemistry extracurricular activity group collected broken egg shells and zinc sheets from used batteries, and prepared clarified lime water, preparing to use it as shown in the picture provided by the tutor. Use instruments and medicines to conduct experiments on preparing gases.

(1) Please select the instruments and medicines needed to produce carbon dioxide gas from the picture (fill in the serial number)

(2) Write the chemical equation for the reaction to produce carbon dioxide: < /p>

(3) Place a short burning candle into an instrument filled with carbon dioxide and observe the candle

Quickly take out the candle and pour in some clear lime water to shake and observe The phenomenon is.

(4) Remove the instrument for producing carbon dioxide and replace it with another to produce another pure gas.