1, the speed formula of uniform linear motion:
Find the speed: v=s/t
Find the distance: s=vt
Discovery time: t=s/v
2. the speed formula of variable-speed linear motion: v = s/t.
3. The relationship between the weight and mass of an object: G=mg (g=9.8N/kg).
4. Definition of density
Find the density of matter: ρ = m/v.
Find the mass of matter: m = ρ v.
Find the volume of matter: V=m/ρ
4. Pressure calculation.
Definition: p=F/S (substances can be used in any state)
Liquid pressure: p=ρgh(h is depth)
Find the pressure: F=pS
Find the stress area: s = f/p.
5. Calculation of buoyancy
Weighing method: f floating = g-f
Formula: F float =G row = ρ row V row G
Float method: F float =G object (V row < V object).
Suspension method: F float =G object (V row =V object)
6. Lever balance condition: F 1L 1=F2L2.
7. definition of work: W=Fs
8. power definition: P=W/t
For uniform linear motion: P=Fv (F is a power)
9. Mechanical efficiency: η = useful power/total power
For lifting objects:
W useful =Gh(h is height)
W total =Fs
10, slope formula: FL=Gh.
1 1, heat absorption and heat release when the temperature of the object changes
Q suction = cm Δ t (Δ t = t-t0)
Q amplifier = cm δ t (δ t = t0-t)
12. Calculation of heat released by fuel combustion: Q =qm.
13, heat balance equation: q absorption =Q discharge.
14, heat engine efficiency: η=W useful /Q amplifier (q amplifier =qm)
15, current definition: I=Q/t (Q is electric quantity in coulomb).
16, ohm's law: I=U/R
Deformation voltage: U=IR
Deformation resistance: r = u/i.
17. Features of series circuit: (Take two pure resistance appliances in series as an example)
Voltage relation: U=U 1+U2
Relationship of current: I=I 1=I2.
Resistance relation: R=R 1+R2.
18. Features of parallel circuit: (Take two pure resistance appliances in parallel as an example)
Voltage relation: U=U 1=U2.
Relationship of current: I=I 1+I2.
Resistance relation:1/r =1/r1+1/R2.
19, electric work calculation: W=UIt.
20. the definition of electricity is p = w/t: p = w/t.
Common formula: P=UI
2 1, Joule's law: Q amplifier =I2Rt
For pure resistance circuit: Q amplifier = I2RT = U2T/R = UIT = Pt = UQ = W.
22. Calculation of total power of lighting circuit: P = P 1+P 1+ ...
All chemical formulas in junior high school
combination reaction
1. Magnesium burns in air: 2Mg+O2 ignites 2MgO.
2. Iron burns in oxygen: 3Fe+2O2 ignites Fe3O4.
3. Aluminum burns in air: 4Al+3O2 ignites 2Al2O3.
4. Hydrogen burns in air: 2H2+O2 ignites 2H2O.
5. Red phosphorus burns in air: 4P+5O2 ignites 2P2O5.
6. Sulfur powder burns in air: S+O2 ignites SO2.
7. Complete combustion of carbon in oxygen: C+O2 ignites CO2.
8. Incomplete combustion of carbon in oxygen: 2C+O2 ignites 2CO.
9. Carbon dioxide passes through the hot carbon layer: C+CO2, high temperature 2CO.
10. Carbon monoxide burns in oxygen: 2CO+O2 ignites 2CO2.
1 1. Reaction of carbon dioxide with water (carbon dioxide is introduced into litmus purpurea test solution): CO2+H2O === H2CO3.
12, quicklime dissolved in water: CaO+H2O === Ca(OH)2.
13, anhydrous copper sulfate as desiccant: cuso 4+5H2O = = = = cuso 4·5H2O.
14. Sodium burns in chlorine: 2Na+Cl2 ignites 2NaCl.
decomposition reaction
15, oxygen production with hydrogen peroxide in the laboratory: 2H2O2 MnO2 2H2O+ O2↑ =
16, heating potassium permanganate: 2KMnO4 heating k2mno4+MnO2+O2 =
17, water decomposition under the action of direct current: 2H2O charged 2H2 =+O2 =
18, unstable decomposition of carbonic acid: H2CO3 === H2O+CO2↑ = =
19. Calcined limestone at high temperature (industrial preparation method of carbon dioxide): CaCO3, high temperature CaO+CO2↑ =
displacement reaction
20. The reaction between iron and copper sulfate solution: Fe+CuSO4 == FeSO4+Cu.
2 1, reaction of zinc with dilute sulfuric acid (hydrogen production in laboratory): Zn+Zn+H2SO4 == ZnSO4+H2↑ =
22. the reaction of magnesium with dilute hydrochloric acid: mg Mg+ 2HCl === MgCl2+H2↑ =
23. Reduction of copper oxide by hydrogen: H2+ copper oxide heats copper +H2O.
24. Reduction of copper oxide with charcoal: 2Cu, high temperature 2Cu+CO2↑ =
25. Methane burns in air: CH4+2O2 ignites CO2+2H2O.
26. Water vapor passes through the hot carbon layer: H2+CO+C, high temperature H2+Co.
27. Reduction of iron oxide by coke: 3C+ 2Fe2O3, high temperature 4Fe+3CO2↑ =
other
28. The reaction between sodium hydroxide solution and copper sulfate solution: 2NaOH+CuSO4 == Cu(OH)2↓+Na2SO4.
29. Methane burns in air: CH4+2O2 ignites CO2+2H2O.
30. Alcohol burns in the air: C2H5OH+3O2 ignites 2CO2+3H2O.
3 1. Reduction of copper oxide by carbon monoxide: CO+ CuO heats Cu+CO2.
32. Carbon monoxide reduces iron oxide at high temperature: 3CO+ Fe2O3, 2Fe+3CO2.
33. Clarify carbon dioxide (CO2) produced by limewater: Ca (OH) 2+CO2 = = = CaCO3 ↓+H2O+H2O.
34, sodium hydroxide and carbon dioxide reaction (carbon dioxide removal): 2 NaOH+CO2 = = = Na2CO3+H2O.
35. The reaction between limestone (or marble) and dilute hydrochloric acid (carbon dioxide is prepared in the laboratory): CaCO3+2hcl = = CaCl2+H2O+CO2 =
36. The reaction of sodium carbonate with concentrated hydrochloric acid (foam extinguisher's principle): Na2CO3+2HCl = = 2NaCl+H2O+CO2 =
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.
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