6FeO+O2===2Fe3O4
FeO+4HNO3===Fe(NO3)3+NO2+2H2O
FeO+4H++NO3？ =Fe3++NO2↑+2H2O
2. Oxidation:
Na2O2+2Na 2Na2O (this reaction is used to prepare Na2O)
MgO and Al2O3 are hardly oxidized, so they are difficult to be reduced to Mg and Al. Usually, magnesium and aluminum are produced by electrolysis.
Fe2O3+3H2 2Fe+3H2O (preparation of reduced iron powder)
Fe3O4+4H2 3Fe+4H2O CuO+H2 Cu+H2O
2 fe3o 4+ 16HI = = 6 Fei 2+8H2O+2 I2
2Fe3O4+ 16H++4I？ =6Fe2++8H2O+2I2
Fe2O3+Fe 3FeO (adding scrap steel as oxidant during steelmaking)
FeO+C Fe+CO (adjusting carbon content in high temperature steelmaking)
2FeO+Si 2Fe+SiO2 (adjusting silicon content in high temperature steelmaking)
3. Interaction with water:
Na2O+H2O==2NaOH
Na2O+H2O=2Na++2OH-
2Na2O2+2H2O===4NaOH+O2↑
2na 2 o 2+2H2O = 4Na ++ 4OH –+ O2↑
(This reaction is divided into two steps: Na2O 2+2H2O = = 2 NaOH+H2O 2；; The preparation of 2h2o 2 = = 2h2o+O2 H2O2 can be done by a similar reaction: BaO2+H2SO4 (dilute) = ===BaSO4+H2O2).
Magnesium oxide +H2O = = magnesium hydroxide (slow reaction)
4. Interaction with acidic substances:
Na2O+SO3 = = na2so 4 Na2O+CO2 = = na2co 3 MgO+SO3 = = = mgso 4
Na2O+2HCl==2NaCl+H2O
Na2O+2H+=2Na++H2O
2na 2 o 2+2co 2 = = 2na 2 co 3+O2↓
Na2O2+H2SO4 (cold, diluted) = ===Na2SO4+H2O2
Magnesium oxide+sulfuric acid = = = magnesium sulfate +H2O
Magnesium oxide +2H+= magnesium +H2O
Al2O3+3H2SO4===Al2(SO4)3+3H2O
Al2O3+6H+=2Al3++3H2O
Al2O3+2NaOH = = 2NALO2+H2O (Al2O3 amphoteric oxide)
Al2O3+2OH？ =2AlO2？ +H2O
FeO+2HCl===FeCl2+H2O
Feo +2H+=Fe2++H2O
Fe2O3+6HCl===2FeCl3+3H2O
Fe2O3+6H+=2Fe3++3H2O
Fe3O4+8HCl===FeCl2+2FeCl3+4H2O
Fe3O4+8H+=2Fe3++Fe2++4H2O
5. Chemical equations related to oxygen:
2Mg+O2 ignition = = = 2 MgO phenomenon: combustion, while releasing a lot of heat and dazzling white light.
S+O2 ignition = ====SO2 phenomenon: the air is a light blue flame; Pure oxygen is a blue-purple flame; At the same time, it produces gas with pungent smell.
C+O2 ignition = ====CO2 phenomenon: gas that can make the clarified lime water turbid is generated.
2C+O2 ignition = ====2CO phenomenon: combustion.
4P+5O2 ignition = ====2P2O5 phenomenon:: white smoke is produced.
3Fe+2O2 Ignition = ====Fe3O4 Phenomenon: Burning violently, sparks everywhere, producing black solids.
2H2+O2 ignition = ====2H2O phenomenon: light blue flame.
2h2o 2mno2 = = = 2h2o+O2 ↑ phenomenon: a large number of bubbles appear in the solution.
2HGO△ = = = 2HG+O2 ↑ phenomenon: silvery white liquid metal is produced.
2kcl3mno2 = = = 2kcl+3o2 ↑ phenomenon: gas is produced that can reignite the wood strips with Mars.
2kmno4 △ = = = k2mno4+MnO2+O2 ↑ phenomenon: same as above,
6. Chemical equations related to hydrogen:
2H2+O2 ignition = ====2H2O phenomenon: light blue flame.
Zn+H2SO4 = = ZnSO4+H2 phenomenon: combustible gas is generated.
Magnesium+sulfuric acid = = magnesium sulfate +H2 = phenomenon: same as above.
Fe+H2SO4==FeSO4+H2↑ Phenomenon: it becomes a light green solution and releases gas at the same time.
2al+3H2SO4 = = Al2 (SO4) 3+3H2 phenomenon: gas is generated.
Zn+2hcl = = zncl2+H2 phenomenon: same as above.
Mg+2hcl = = MgCl2+H2 phenomenon: same as above.
Fe+2HCl = = FeCl 2+H2 phenomenon: the solution turns pale green and gas is released at the same time.
2Al+6HCl = = 2AlCl3+3H2 phenomenon: gas is generated.
H2+CuO = = = Cu+H2O phenomenon: black solid turns red, and water droplets are generated at the same time.
2Fe2O3+3H2 = = = = 2Fe+3H2O phenomenon: water droplets are generated, and the solid color changes from red to silvery white.
7. Chemical equations related to carbon:
C+O2 ignition = ====CO2 (under the condition of sufficient oxygen) phenomenon: gas that can make pure lime water turbid is generated.
2C+O2 = = = = 2CO fire (under the condition of insufficient oxygen) phenomenon: not obvious.
C+2cuo = = = 2cu+CO2 ↑ phenomenon: the solid changes from black to red and decreases, and at the same time, it produces gas that can make pure lime water turbid.
3C+2Fe2O3 = = = = 4Fe+3CO2 ↑ Phenomenon: The solid gradually changes from red to silvery white, and at the same time, the black solid decreases, producing gas that can make pure lime water turbid.
CO2+C high temperature = ====2CO phenomenon: black solids gradually decrease.
3C+2H2O=CH4+2CO phenomenon: The generated mixed gas is called water gas, which is flammable.
8. Chemical equations related to carbon dioxide:
C+O2 ignition = ====CO2 phenomenon: gas that can make pure lime water turbid is generated.
Ca (OH) 2+CO2 = = CaCO3 ↓+H2O phenomenon: white precipitate is generated and used to test carbon dioxide.
CaCO3+CO2+H2O = = Ca (HCO3) 2 phenomenon: white solid gradually dissolves.
Ca (HCO3) △ = = = CaCO3 ↓+CO2 ↑+H2O phenomenon: white precipitate is generated, and at the same time, gas that can make pure lime water turbid is generated.
Cu2 (OH) 2co3△ = = 2cuo+H2O+CO2 ↑ Phenomenon: The solid gradually turns from green to black, and at the same time, there is gas that can make pure lime water turbid.
2 NaOH+CO2 = = Na2CO3+H2O (or KOH) phenomenon: not obvious.
CaCO3 high temperature = = = Cao+CO2 ↑ Phenomenon: gas can make pure lime water turbid.
Metal oxide chemical equation 2 1, high school chemical equation summary
NH4CO3δ NH3 ↑+H2O+CO2 ↑ CO2 ↑ White solid disappears, and there is liquid on the pipe wall, which makes limewater turbid. Ammonium bicarbonate will disappear after long-term exposure to air.
Zn+H2SO4=ZnSO4+H2↑ produces a large number of bubbles, and zinc particles gradually dissolve to prepare hydrogen in the laboratory.
Fe+H2SO4=FeSO4+H2↑ produces a large number of bubbles, and metal particles gradually dissolve.
Mg+H2SO4 =MgSO4+H2↑ produces a large number of bubbles, and metal particles gradually dissolve.
2Al+3H2SO4=Al2(SO4)3+3H2↑ produces a large number of bubbles, and metal particles gradually dissolve.
The red color of Fe2O3+3H2δ 2Fe+3H2O gradually turns silvery white, and there is liquid molten metal on the wall of the test tube, which is reduced by hydrogen.
Fe3O4+4h2δ 3fe+4h2o black gradually turns silvery white, and there is liquid molten metal on the wall of the test tube, which is reduced by hydrogen.
Tungsten smelting by WO3+3H2Δ W +3H2O and reduction by hydrogen.
Molybdenum Smelting with moo 3+3h 2δMo+3H2O and Reduction of Hydrogen
The intense combustion of 2Na+Cl2δδ or the ignition of 2NaCl, the formation of yellow flame ionic compounds,
Ignite with H2+Cl2 or light flame with 2HCl irradiation to form white mist at the bottle mouth, and prepare hydrochloric acid.
CuSO _ 4+2 NaOH = Cu (OH) _ 2 ↓+Na _ 2SO _ 4 There is a blue precipitate of clear solution at the top of the experiment.
The common reaction of 2C +O2 igniting a 2CO coal stove is one of the air pollutants and the cause of gas poisoning.
2C O+O2 ignites 2CO2 blue flame gas for combustion.
At high temperature of C+CuO, 2Cu+ CO2↑ black gradually turns red, and gas is generated to make clear limewater turbid.
Through the study of the summary knowledge of chemical equations in grade three, I believe that the students have mastered the knowledge of the above equations well, and I hope that the students will succeed in the exam.
A summary of the equations of natural water in junior middle school chemistry
2. Water in nature:
17. Decomposition of water under the action of direct current (experimental study on composition of water): 2H2O electrified 2H2 =+O2 =
18. quicklime is soluble in water: CaO+H2O == Ca(OH)2.
19. Carbon dioxide is soluble in water: H2O+CO2==H2CO3.
I believe that students have mastered the explanation of chemical equations related to water in nature, and I believe they will learn a lot from them.
Summary and explanation of the property equation of oxygen in junior middle school chemistry
For the equation learning of the knowledge of the properties of oxygen in chemical equations, students look at the following contents carefully.
3, the nature of oxygen:
(1) Reaction of simple substance with oxygen: (combination reaction)
1. Magnesium burns in oxygen: 2Mg+O2 ignites 2MgO.
2. Iron burns in oxygen: 3Fe+2O2 ignites Fe3O4.
3. Copper heating in oxygen: 2Cu+O2 heating 2CuO.
4. Aluminum burns in oxygen: 4Al+3O2 ignites 2Al2O3.
5. Hydrogen burns in oxygen: 2H2+O2 ignites 2H2O.
6. Combustion of red phosphorus in oxygen (experiment to study air composition): 4P+5O2 ignites 2P2O5.
7. Sulfur burns in oxygen: 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 oxygen: CH4+2O2 ignites CO2+2H2O.
12. Alcohol burns in oxygen: C2H5OH+3O2 ignites 2CO2+3H2O.
(3) Oxygen
13. lavoisier studied the composition of air. Experiment 2hg 0 heated 2 Hg+O2 =
14. heating potassium permanganate: 2KMnO4 heating k2mno4+MnO2+O2 = (principle of oxygen production in laboratory 1)
15. heating the mixture of potassium chlorate and manganese dioxide: 2KClO3 = heating MnO2 = 2kCl+3o2 = (principle of oxygen production in the laboratory 2)
16. decomposition of hydrogen peroxide with manganese dioxide as catalyst: 2h2o2 = MnO2 = 2h2o+O2 = (principle 3 of oxygen production in laboratory)
Photosynthesis of plants: 6CO2+6H2O sunlight/chlorophyll 6O2+C6H 12O6.
I hope it will be good to learn the summary knowledge of the property equation of oxygen in chemistry. I believe the students will get good grades in the exam. Let's go
Summary and explanation of balancing method of chemical equation in junior middle school
balancing method
1, least common multiple method
A, find out the atoms with more atoms on both sides of the reaction formula and a single pair, and find the least common multiple.
B, deduce the coefficient of each molecule. go home
For example:
Step 1: copper sulfate+sodium hydroxide-copper hydroxide+sodium sulfate.
Step 2: CuSO4+2 NaOH-Cu (OH) 2+Na2SO4 (balanced hydroxide)
Step 3: CuSO4+2 NaOH = = Cu (OH) 2 ↓+Na2SO4 (indicate the product state).
2. Observation method
Calculating the stoichiometric ratio of each reactant chemical formula and the stoichiometric ratio of the product from the product with complex chemical formula; According to the stoichiometry of the obtained chemical formula, find out the stoichiometry of other chemical formulas until it is balanced.
For example: Step 1: H2O(g)+Fe-fe3o 4+H2.
Step 2 4h20 (g)+3fe-Fe3O4+H2
Step 3: 4H20 (g)+3Fe = = Fe3O4+4H2 (reaction condition: heating) reunion.
3. Parity balance method
See which element appears most frequently on the left and right sides of the reaction chemical equation; Starting from the odd chemical molecular formula of the element, make it even (that is, the stoichiometric number is 2); The stoichiometry obtained from it balances the stoichiometry of other chemical formulas, making the number of atoms on both sides equal.
Example: Balance
H2O+ Fe-Fe3O4+H2
Step 1: Balance oxygen atoms.
4H2O(g)+Fe - Fe3O4+H2
Step 2: Balance hydrogen and iron atoms.
4H2O(g)+3Fe - Fe3O4+4H2
Step 3: Chemical equation after balance:
4h2o (g)+3fe = = Fe3O4+4h2 = (reaction condition: heating).
4. Stoichiometric method to be determined
Different unknowns represent the stoichiometric ratio of each chemical formula in the chemical equation; According to the law of conservation of mass, the types of atoms are the same before and after the reaction, and the number of atoms is equal, and the mathematical equations are listed. Solve the equations, find any unknown number 1, and find the values of other unknown numbers; Finally, the unknown value is substituted into the original chemical equation.
For example: NH3+Cl2-NH4Cl+N2
Let the stoichiometry of each substance be a, b, c and d in turn.
Acrylonitrile +bCl2-cNH4Cl+dN2
Equation set a=c+2d (the number of nitrogen atoms is equal)
3a=4c (equal number of hydrogen atoms)
2b=c (equal number of chlorine atoms)
Let b= 1 and the solution is: a=8/3, c=2, d= 1/3.
8nh3+3cl2 = = = 6nh4cl+N2 (A A, B, C and D are all enlarged by 3 times, because the coefficient cannot be decimal).
5. Price fluctuation method
First, the principle of equilibrium Due to the transfer of electrons in the redox reaction, the valence of elements is bound to rise and fall. We call elements whose valence can rise or substances containing them reducing agents. On the contrary, it is called oxidant. From the knowledge of redox reaction, we can easily draw the equilibrium principle: the total number of electrons lost by reductant = the total number of electrons gained by oxidant, that is, the total number of price increases of reductant (element) = the total number of price reductions of oxidant (element).
Second, the general method and steps to balance the redox reaction equation
1, general method: from left to right.
2. Steps: convert the price, find the change, find the total amount and match the coefficient.
Namely:
(1) Mark the initial and final valence states of the changing elements;
⑵ Total price of initial state and final state change = change amount × coefficient
Note: It is assumed that all the above changes are expressed in positive prices, where (b-a)×(d-c) is the least common multiple.
(3) Fill the coefficients in the table before the chemical formulas of reducing agent and oxidizing agent respectively, and use them as coefficients;
(4) Balance other elements through observation;
5] Check whether the equilibrium equation conforms to the law of conservation of mass (ion equation also depends on whether it conforms to the law of conservation of charge).
6. Oxygen acquisition and oxygen loss method
For redox reaction, the oxygen loss number of oxidant is observed first, then the oxygen gain number of reductant is observed, and then the equilibrium is carried out.
For example: 3co+Fe2O3 = = = 2fe+3co2.
Oxidizer iron oxide loses three oxygen before and after the reaction, and reductant carbon monoxide gains one oxygen before and after the reaction, so it takes three carbon monoxide to take away the oxygen in iron oxide, carbon monoxide and carbon dioxide are matched with 3, and iron is matched with 2.
Through the explanation of the above chemical equation balancing method, I believe students can master the above knowledge well, and I hope students can get good grades in the exam.
Explanation of reactant state of junior middle school chemical equation
For the explanation of the state knowledge of reactants in chemistry, I hope students can master the following contents well.