最新高中化学关键知识点易错辨析复习过程
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高中化学关键知识点易错辨析（The key point of high school chemistry knowledge error）The key point of high school chemistry knowledge error
Knowledge module of element compounds 1. the larger the atomic radius of the alkali metal element, the higher the melting point, the greater the activity of the elementary substance
The melting point decreases as the radius of the atom increases All 2. sulfur and white phosphorus soluble in carbon disulfide, carbon tetrachloride and other organic solvent, organic acid is insoluble in water
Error: lower organic acids are soluble in water 3. add enough concentrated sulfuric acid to produce blue solid in a saturated solution of copper sulphate
Right, concentrated sulfuric acid water after precipitation with vitriol
4. the only elements that can react with cold water to emit gaseous matter are active metallic elements or active nonmetallic elements
For example, 2Na2O2+2H2O error, O2 = +4NaOH 5. liquefy the air and then gradually heat up, first producing oxygen, and remaining nitrogen
Error, the boiling point of N2 is below O2, and N2 is first obtained, leaving liquid oxygen
6. smelting pig iron into carbon steel, the main problem is to remove the pig iron in addition to various elements except Fe, pig iron purification
The mistake is to reduce the percentage of C in pig iron, not to purify it
7. although potassium in nature is soluble in water, but K% in soil is not high, so it is necessary to use potassium fertilizer to meet the needs of plant growth
The potassium content in nature is not low, but it exists in the form of complex silicate and is difficult to dissolve in water
8. preparation of bleaching powder, preparation of Bordeaux and modified acid soil, lime should be used
Right, preparation of lime and bleaching powder for Cl2 reaction, Bordeaux mixture of copper sulfate and hydrated lime
9. silica is an acid oxide which is insoluble in acid solutions Error, SiO2 can be dissolved in hydrofluoric acid 10. iron excess soluble in hydrochloric acid, then adding chlorine or bromine or iodine or zinc nitrate, all can produce Fe3+
Error adding iodine water will result in FeI2, because the oxidation of Fe3+ is not as good as Cl2, Br2, but stronger than I2, and FeI3 does not exist in solution
11. at room temperature, concentrated nitric acid can be stored in aluminum cans, indicating that aluminum and concentrated nitric acid do not respond
Error, passivation is a chemical property that essentially produces a dense Al2O3 oxide film that protects the aluminum cans
12.NaAlO2, Na2SiO3, Na2CO3, Ca (ClO) 2, NaOH, C17H35COONa, C6H5ONa and other saturated solution into the white precipitate CO2, continue to pass into the CO2 to excess, white precipitation still does not disappear
Error, Ca (ClO) 2 continues to pass through CO2 to excess, white precipitate disappears, and finally gets Ca (HCO3) 2
13. a large amount of sulfur dioxide in the atmosphere is derived from the combustion of coal and petroleum and the smelting of metal ores
Correct 14., a clear solution by NH4Cl, AgNO3, NaOH three substances mixed into, and if you add sufficient nitric acid, white precipitate will be produced
Correct, NH4Cl, AgNO3 and NaOH react after mixing to form [Ag (NH3) 2]+
Add sufficient nitric acid to produce AgCl and NH4NO3 15., in order to make full use of raw materials, the tail gas in sulfuric acid industry must be purified and recovered
The mistake is to prevent air pollution 16. the reaction of 1molAl with sufficient NaOH solution leads to the transfer of 3mol electrons
Correct 17. sodium sulfide can neither react with caustic soda nor react with hydrogen sulfate
Error, sodium sulfide can react with hydrogen sulfate: Na2S+H2S====2NaHS
18. in a solution containing high concentration of Fe3 + in it, I, AlO, S2, CO32-, HCO3-, not a lot of coexistence
Properly, Fe3+ can react with SCN-, react with I- and S2-, and undergo double hydrolysis with CO32-, HCO3- and AlO2-
19. activated carbon, sulfur dioxide, chlorine, etc. can make
