Tonghua county experimental primary school Wu nian San ban Xin Li
Everything in the world, we should all be moved. Because they deserve our trust and touch. Even a butterfly deserves our touch and respect.
Yes, even a butterfly, a butterfly that is not beautiful. But it touched me.
The autumn wind is rustling. God, it's ridiculously blue. Clouds on a blue background. In the background of the pool, all kinds of postures. The cool wind embraced the leaves on the branches. The sunshine is soft. On the way home slowly, I walked at a lazy pace. Looking for everything that deserves my respect and affection.
A butterfly, a white butterfly. Struggling in the pool, microwave waves appeared on the water. I leaned down and murmured, "Why do you insist? Give it up. No one will care about you, don't force it. " I was wrong. Yes, if this butterfly dies in the pool, no one will notice and no one will care. However, it cares. Care about its insignificant life, care about the short happiness in its life. This butterfly has been struggling, and it wants to survive! I am moved by its persistence and concern for life!
I picked it up with my hand, water, very cold. In the pool where the butterfly left, the sky and white clouds were quiet. What moved me most was that the butterfly only stayed on the shore for a few minutes before spreading its wings and flying. White wings fly with it, showing happiness and happiness under the sunshine.
This is very touching. A butterfly that moved me. Yes, it is a butterfly, even if it is not beautiful.
Urgent! Archive the files after being admitted to colleges and universities! ! ! Urgent, then take the admission notice to the original school. They moved it away and then asked them to move it back. If you don't move, find a group of your family to make trouble there. There is only one file, which records all kinds of records from primary school to middle school. When colleges and universities want archives, they also need to record things in the archives. Without a file, even if you get an undergraduate certificate, it doesn't count. The documents will follow you after work.
Urgent, now a chemistry problem of grade three is coming. The most important thing in urgent chemistry is to try equations, so you must master the summary of chemical equations.
I. Reaction of substances with oxygen:
(1) the reaction of simple substance with oxygen;
1. Magnesium burns in air: 2Mg+O2 ignites 2MgO.
2. Iron burns in oxygen: 3Fe+2O2 ignites Fe3O4.
3. Copper heating in air: 2Cu+O2 heating 2CuO.
4. Aluminum burns in air: 4Al+3O2 ignites 2Al2O3.
5. Combustion in hydrogen and air: 2H2+O2 ignites 2H2O.
6. Red phosphorus burns in air: 4P+5O2 ignites 2P2O5.
7. Sulfur powder burns in air: S+O2 ignites SO2.
8. Complete combustion of carbon in oxygen: C+O2 ignites CO2.
9. Incomplete combustion of carbon in oxygen: 2C+O2 ignites 2CO.
(2) the reaction of compounds with oxygen:
10. Carbon monoxide burns in oxygen: 2CO+O2 ignites 2CO2.
1 1. Methane burns in air: CH4+2O2 ignites CO2+2H2O.
12. Alcohol burns in air: C2H5OH+3O2 ignites 2CO2+3H2O.
2. Several decomposition reactions:
13. Decomposition of water under direct current: 2H2O charged 2H2 =+O2 =
14. heating basic copper carbonate: Cu2(OH)2CO3 heating 2cuo+H2O+CO2 =
15. heating potassium chlorate (containing a small amount of manganese dioxide): 2kClO3 = = = 2kCl+3o2 =
16. heating potassium permanganate: 2KMnO4 heating k2mno4+MnO2+O2 =
17. Carbonic acid is unstable and decomposed: H2CO3 === H2O+CO2↑ =
18. high temperature calcined limestone: CaCO3, high temperature CaO+CO2↑ =
Three. Several redox reactions:
19. Reduction of copper oxide by hydrogen: H2+ copper oxide heats copper +H2O.
20. Reduction of copper oxide with charcoal: 2Cu, high temperature 2Cu+CO2↑ =
2 1. Iron oxide reduction by coke: 3C+ 2Fe2O3, high temperature 4Fe+3CO2↑ =
22. Reducing Fe3O4 with coke at high temperature: 2c+Fe3O4, 3Fe+2 CO2 =
23. Reduction of copper oxide by carbon monoxide: CO+ CuO heats Cu+CO2.
24. Reduction of iron oxide by carbon monoxide: 3CO+ Fe2O3, high temperature, 2Fe+3CO2.
25. Reduction of ferroferric oxide with carbon monoxide: 4CO+ Fe3O4, high temperature 3Fe+4CO2.
4. Relationship among simple substance, oxide, acid, alkali and salt
(1) elemental metal+acid salt+hydrogen (displacement reaction)
26. Zinc and dilute sulfuric acid Zn+H2SO4 = ZnSO4+H2 Write
27. Iron and dilute sulfuric acid Fe+H2SO4 = FeSO4+H2 Write
28. magnesium and dilute sulfuric acid mg+H2SO4 = mgso4+H2 write
29. Aluminum and dilute sulfuric acid 2Al +3H2SO4 = Al2(SO4)3 +3H2↑ 3+3H2+3H2 write 3+3H2.
30. Zinc and dilute hydrochloric acid Zn+Zn+2HCl === ZnCl2+H2↑ =
3 1. Iron and dilute hydrochloric acid Fe+2 Fe+2HCl === FeCl2+H2↑ = H2 =
32. Magnesium and dilute hydrochloric acid Mg Mg+ 2HCl === MgCl2+H2↑ =
33. Aluminum and dilute hydrochloric acid 2Al+6HCl = = 2AlCl3+3H2 Write
(2) Simple metal+salt (solution)-another metal+another salt
34. The reaction between iron and copper sulfate solution: Fe+CuSO4 = = FeSO4+Cu.
35. The reaction between zinc and copper sulfate solution: Zn+CuSO4 = = ZnSO4+Cu.
36. The reaction between copper and mercury nitrate solution: Cu+Hg (NO3) 2 = = Cu (NO3) 2+Hg.
(3) Alkaline oxide+acid salt+water
37. The reaction of iron oxide with dilute hydrochloric acid: Fe2O3+6HCl === 2FeCl3+3H2O+3H2O.
38. Reaction of iron oxide with dilute sulfuric acid: Fe2O3+3H2SO4 = = Fe2 (SO4) 3+3H2O+3H2O.
39. Reaction of copper oxide with dilute hydrochloric acid: CuO+2hcl = = = CuCl2+H2O.
40. The reaction between copper oxide and dilute sulfuric acid: CuO+H2SO4 = = = CuSO4+H2O.
4 1. The reaction of magnesium oxide with dilute sulfuric acid: MgO+H2SO4 = = = MgSO4+H2O.
42. The reaction of calcium oxide with dilute hydrochloric acid: Cao+2 HCl = = = CaCl2+H2O.
(4) acidic oxide+alkaline salt+water
43. Caustic sodium will deteriorate when exposed to air: 2NaOH+CO2 ==== Na2CO3+H2O.
44. Caustic sodium absorbs sulfur dioxide gas: 2 NaOH+SO2 = = = Na2SO3+H2O.
45. Caustic sodium absorbs sulfur trioxide gas: 2NaOH+SO3 ==== Na2SO4+H2O.
46. The slaked lime deteriorates in the air: Ca (OH) 2+CO2 = = = CaCO3 ↓+H2O+H2O.
47. The slaked lime absorbs sulfur dioxide: ca (oh) 2+SO2 = = = caso3 ↓+H2O+H2O.
(5) acid+alkali-salt+water
48. Reaction of hydrochloric acid with caustic soda: HCl+NaOH = = = NaCl+H2O.
49. Reaction of hydrochloric acid and potassium hydroxide: HCl+KOH = = = KCl+H2O.
50. The reaction between hydrochloric acid and copper hydroxide: 2HCl+Cu (OH) 2 = = CuCl2+2H2O.
5 1. The reaction between hydrochloric acid and calcium hydroxide: 2hcl+Ca (OH) 2 = = CaCl2+2h2o.
52. The reaction between hydrochloric acid and iron hydroxide: 3HCl+Fe (OH) 3 = = = FeCl 3+3H2O.
53. Aluminum hydroxide for the treatment of hyperacidity: 3HCl+Al (OH) 3 = = = AlCl3+3H2O.
54. Reaction between sulfuric acid and caustic soda: H2SO4+2NaOH = = = Na2SO4+2H2O.
55. The reaction between sulfuric acid and potassium hydroxide: H2SO4+2koh = = = K2SO4+2h2o.
56. The reaction between sulfuric acid and copper hydroxide: H2SO4+Cu (OH) 2 = = CuSO4+2H2O.
57. The reaction between sulfuric acid and iron hydroxide: 3H2SO4+2Fe (OH) 3 = = Fe2 (SO4) 3+6H2O.
58. The reaction between nitric acid and caustic soda: nitric acid+sodium hydroxide = = = sodium nitrite+H2O H2O.
(6) acid+salt-another acid+another salt
59. marble reacts with dilute hydrochloric acid: CaCO3+2hcl = = CaCl2+H2O+CO2 =
60. Sodium carbonate reacts with dilute hydrochloric acid: Na2CO3+2HCl = = 2NaCl+H2O+CO2 =
6 1. Reaction of magnesium carbonate with dilute hydrochloric acid: MgCO3+2HCl = = MgCl2+H2O+CO2 =
62. Reaction between hydrochloric acid and silver nitrate solution: HCl+AgNO3 === AgCl↓+HNO3.
63. The reaction of sulfuric acid and sodium carbonate: Na2CO3+H2SO4 = = Na2SO4+H2O+CO2 =
64. The reaction between sulfuric acid and barium chloride solution: H2SO4+bacl2 = = = baso4 ↓+2hcl.
(7) alkali+salt-another alkali+another salt
65. Sodium hydroxide and copper sulfate: 2 NaOH+CuSO4 = = Cu (OH) 2 ↓+Na2SO4.
66. Sodium hydroxide and ferric chloride: 3 NaOH+FeCl 3 = = Fe (OH) 3 ↓+3 NaCl.
67. Sodium hydroxide and magnesium chloride: 2 NaOH+MgCl2 = = mg (OH) 2 ↓+2 NaCl.
68. Sodium hydroxide and copper chloride: 2 NaOH+CuCl2 = = Cu (OH) 2 ↓+2 NaCl.
69. Calcium hydroxide and sodium carbonate: Ca (OH) 2+Na2CO3 = = CaCO3 ↓+2NaOH.
(8) salt+salt-two new salts
70. Sodium chloride solution and silver nitrate solution: NaCl+AgNO3 = = = AgCl ↓+Nano3.
7 1. sodium sulfate and barium chloride: Na2SO4+bacl2 = = = baso4 ↓+2 NaCl.
Verb (short for verb) Other reactions:
72. Carbon dioxide is soluble in water: CO2+H2O === H2CO3.
73. Quicklime is soluble in water: CaO+H2O === Ca(OH)2.
74. Sodium oxide is soluble in water: Na2O+H2O = = = 2 NaOH.
75. Sulfur trioxide is soluble in water: SO3+H2O = = = H2SO4.
76. Copper sulfate crystal is decomposed by heat: CuSO4? Heating CuSO4+5H2O
77. Anhydrous copper sulfate as desiccant: CuSO4+5H2O = = = CuSO4? 5H2O
There is such a concept:
Summary of junior high school chemistry knowledge (chemical formula)
1, basic reaction type:
Compound reaction: changeable reaction
Decomposition reaction: one becomes more.
Replacement reaction: one order for one order.
Double decomposition reaction: exchange ions
2. Valence of common elements (positive):
Univalent potassium, sodium, hydrogen and silver,
Bivalent calcium magnesium barium and zinc,
Trivalent metal element aluminum;
157 variable valence chlorine,
245 nitrogen, 46 sulfur,
Three or five have phosphorus, two or four carbons;
One or two copper, two or three iron,
2467 manganese is special.
3, the steps of making oxygen in the laboratory:
"Tea (stop), tea (bag), tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea, tea,
Check the air tightness of the equipment.
"package" the medicine and connect the equipment.
The "fixed" test tube is fixed on the iron frame.
Light the alcohol lamp to keep warm.
Collect gas
"Close" the catheter out of the water.
Turn off the alcohol lamp and stop heating.
4. Experimental steps of reducing copper oxide with CO:
"One pass, two points, three extinctions, four stops and five treatments"
"A mobile phone" is connected with hydrogen first,
After "two o'clock", light the alcohol lamp to keep warm;
After the "three extinctions" experiment, put out the alcohol lamp first.
"Four stops" wait until room temperature before stopping introducing hydrogen;
"Five treatments" to control tail gas and prevent carbon monoxide from polluting the environment.
5, the experimental phenomenon of electrolytic water:
"oxygen positive hydrogen negative, oxygen one hydrogen two":
The anode releases oxygen and the cathode releases hydrogen;
The volume ratio of oxygen to hydrogen is 1: 2.
6. Elements that make up the earth's crust: adopted sons (oxygen, silicon, aluminum).
7. Relationship between outermost atoms and ions and valence formation:
"yang loss is positive, yin gain is negative, and the value remains unchanged":
The outermost atoms lose electrons to form cations, and the valence of elements is positive; The outermost layer of atoms gains electrons to form anions, and the valence of elements is negative; Number of electrons gained or lost = number of charges = valence.
8, chemical experiment basic operation formula:
Solids need spoons or paper slots, one free, two vertical and three elastic;
It is best to use a block or tweezers, one horizontal and two vertical.
The liquid should be put in a flask, labeled by hand, and then poured out.
The reading should be flat with the section, with the head down low and the head down high.
The dropper has a pinch head and is hung vertically without pollution.
Don't forget to clean up when it is uneven.
The balance of the tray should be flat and the screw should be centered;
Put things left and right, and clamp the tweezers first big and then small;
The test paper should be cut down first, and the glass rod is immersed in liquid for the best test effect.
Wet the test paper first, stick it on a stick and lean against the air.
The outer flame of the heating wine lamp is two-thirds of the boundary.
Sulfuric acid is stirred in water and injected slowly to prevent boiling and splashing.
In the experiment, the air tightness is checked first, and the cups and bottles are heated through the net.
After drainage and gas collection, remove the conduit first, and then move the lamp.
9, metal activity sequence:
The order of metal activity from strong to weak is: K Ca Na Mg Al Zn Fe Sn Pb (H) Cu Hg Ag Pt Au (described in turn).
Potassium, calcium, sodium, magnesium, aluminum, zinc, iron, tin, lead (hydrogen), copper, mercury, silver and platinum.
10, "cross method" to write the formula of chemical formula:
"Positive price left negative price right, cross subtraction, write right to test right and wrong."
1 1, filtering operation formula:
The funnel angle of the glass rod and filter paper of the beaker of the bucket frame is the same;
Let stand before filtering, don't forget to tilt three times and two times.
12, the law in the experiment:
(1) When solid is heated to produce gas, potassium permanganate oxygen generator (solid-solid heating type) is selected;
The device for preparing O2 from hydrogen peroxide (solid-liquid unheated type) is used to prepare gas by solid-liquid reaction without heating.
(2) When heating the test tube solid, it should be preheated first, and the test tube mouth is slightly inclined downward.
(3) Any generated gas that is insoluble in water (does not react with water) can be collected by drainage.
Any gas with higher density than air can be collected by exhausting upwards.
Any gas less dense than air can be collected by downward exhaust.
(4) When doing the gas experiment, first check the air tightness of the device, the rubber plug 1-2ml should be exposed on the catheter, and the iron clip should be clamped at the distance from the nozzle 1/3.
⑤ When making gas with a long-necked funnel, the nozzle at the end of the long-necked funnel should be inserted under the liquid surface.
⑥ When igniting combustible gas, you must first check its purity.
⑦ When doing experiments with toxic gases, the tail gas must be finally treated.
⑧ When reducing metal oxides with reducing gas, "one pass, two points, three extinguishes and four stops" must be achieved.
13, reaction law:
Displacement reaction:
(1) Elemental metal+acid → salt+hydrogen
(2) simple metal+salt (solution) → another metal+another salt
(3) metal oxide+charcoal or hydrogen → metal+carbon dioxide or water
Double decomposition reaction:
① Alkaline oxide+acid → salt ++H2O ② Alkali+acid → salt +H2O
③ Acid+salt → new salt+new acid ④ salt 1+ salt 2→ new salt 1+ new salt 2.
⑤ salt+alkali → new salt+new alkali
14, metal+acid → salt+++H2↑ =
(1) metal reacts with enough acid to release hydrogen in the order of Al > Mg > Fe > Zn.
② Different acids with equal mass react with enough metals, and the smaller the relative molecular weight of the acid, the more hydrogen is released.
③ The same acid with the same mass reacts with enough different metals to release the same amount of hydrogen.
(4) After the reaction of metal+acid → salt +H2 ↑, the solution becomes heavier and the metal becomes lighter.
Metal+salt solution → new metal+new salt:
(1) When the relative atomic mass of the metal is greater than that of the new metal,
After the reaction, the mass of the solution becomes heavier and the metal becomes lighter.
(2) When the relative atomic mass of the metal is less than that of the new metal.
After the reaction, the mass of the solution becomes lighter and the metal becomes heavier.
15, catalyst: one change and two unchanged (a substance whose chemical properties and quality are unchanged by changing the reaction rate of a substance is a catalyst).
Oxidant and reductant: oxygen is reduced and deprived (the substance that takes oxygen is reductant, and the substance that loses oxygen is oxidant).
16. Impurity removal connector of gas washing cylinder: long inlet and short outlet.
Connection between drainage and gas collection and washing tank: short in and long out.
Connection between exhaust gas gathering and gas washing cylinder: low density means short inlet and outlet, while high density means long inlet and outlet.
17, experimental impurity removal principle: remove other things first, and then remove water vapor.
Experimental inspection principle: water first, then water.
Is there a secret book on the road to survival? Urgent! Yes, there are many Baidu libraries.
Two-part allegorical saying of China's classic works, Xu Shu hurried into Cao Cao's camp without saying a word.
Li Kui jy hits Song Jiang-After the gift.
Lin Chong went to Liangshan-* * *
We are a family. A warm and anxious home is made up of an understanding mother, a conscientious father and a group of lively and lovely children. Although there are no parents with such personality in my family, my family is still as warm as sunshine.
It is another winter, and the biting cold wind threatens passers-by walking in the streets. Only a few people hide their faces on the road, and most of them hide at home to keep warm.
I am the only one at home. In this lonely and spacious house, I am surrounded by bouts of loneliness. I turned a blind eye and wandered in the corridor. My mood drifted to the outside of the cloud nine, and my footsteps fell down. I went to my parents' room.
My parents' room is elegant and beautiful. There are a series of pictures on the wall with a mysterious feeling. The curtains are Indian style and have a classical taste. The carpet on the floor is made of foreign flowers and the bed is unique. There are many beautiful strings of waves on the ceiling, and crystal-like strange lights are hung. The excited cells in my body keep beating. This is the first time I broke into my parents' room by mistake. My parents didn't allow me to go in before I came in. I walked carefully to the counter and my eyes lit up. There are many perfume brands and cosmetics. I opened the drawer again. Unexpectedly, there is a delicate box inside. Curiosity drove me to open it. I sat on the bed with a box. The soft bed immediately looks like mud. My feet kept swinging and my hand gently opened the box. In fact, it is a very small but clear bottle with some oil in it. I opened the lid and put my nose together to smell. There is a fragrance around my nose. It turned out to be a bottle of perfume. A few minutes later, the door rang, and then there was the sound of keys. I heard my mother calling me. I put the perfume into the box in a panic, but my hand slipped and the perfume bottle fell to the ground like noodles in my hand, spilling "a flower".
Urgent! Urgent! Urgent! Windows can't get in because I forgot my password. Help urgently! Press F8 when starting.
Select Safe Mode with Command Line.
Select Administrator to pop up the Command Prompt window.
To add a new user (for example, user name is abcdef and password is 123456), type "user abcdef 123456 /add".
(After adding, you can use the "local group administrator abcdef/add" command to promote the user to the "administrator" user of the system management group.)
Restart the computer and select the normal mode to run. You can use the modified password "user abcdef password: 123456".
Urgent! ~! ~~~! This is an emergency! Why can't QQ be installed? Does the machine itself have QQ? But when you install a new QQ, you get an error. Can't you uninstall it? If so, then you can download this. Download the msi file from the Internet, and then browse this downloaded. Msi file, you can successfully install your new QQ. I don't know if this is the problem. Don't take offense ... hehe.
Urgent! Urgent! Urgent! How to import music into my QQ music collection? Urgent! Urgent! Urgent! 1: Create a playlist in.
2. Click QQ Music to close the main menu of QQ Music on the left, and then click the X key on the left.
Step 3 click
4: Select a song and confirm it, and it will be OK.
Thank you, that's all. If not, then I don't know.
Does the K2 10 train pass the Beijing-Guangzhou Railway? Urgent! This train also passes through Shaoguan and will be affected.
The notice of this train stop can not be found for the time being, subject to the announcement of the station on that day.