The substance is the impurity C contained in the KUO, what is used to remove the impurity?

The first problem, the solution is combustion, which is simple and easy, the carbon becomes carbon dioxide gas, and the copper oxide has no effect. The second problem, the solution is to dissolve, sodium carbonate is soluble, barium carbonate is insoluble, and then the solid filtered is barium carbonate, which is also very simple, fast and efficient.

The first is that if the copper oxide is mixed with carbon impurities, you can't use the combustion method, because it is likely that a part of the copper oxide will be reduced by carbon during the combustion process, and the mixture can be put into the water, and the copper oxide is dense, and the carbon will sink to the bottom, and the carbon will float on it, and then go out and carbon filter.

The second is to use the method of dissolution to get out of the sodium carbonate in the barium carbonate, because the barium carbonate is insoluble, and the sodium carbonate is soluble in water, so it can go out.

First of all, you can't burn it, because copper oxide and carbon react to form copper and co, and you can't put it in water, because both are denser than water

There seems to be no direct way, but the mixture can be heated at high temperatures by placing it in oxygen or air, so that even if copper oxide and carbon react to form copper and co co, they are gases, and after the carbon reaction is completed, the copper element can continue to react with oxygen to form copper oxide again

Supplementary question: Barium carbonate is insoluble, while sodium carbonate is soluble, just dissolve and filter directly

Combustion because C will turn into carbon dioxide and copper oxide will not be burned.

Cu and O2 generate copper oxide under heating conditions, which can remove impurities without introducing new impurities, which is in line with the principle of impurity removal. The chemical equation of the reaction is 2Cu+O2 2CuO, which conforms to the characteristics of "multiple and one changeables" and belongs to the chemical reaction CaCO3 calcination at high temperature to generate calcium oxide and carbon dioxide, which can remove impurities and does not introduce new impurities, which conforms to the principle of impurity removal; The chemical equation of the reaction is CaCO3 high temperatureCaO+CO2, the reaction conforms to the characteristics of "one becomes many", belongs to the decomposition reaction To remove Cuso4 in Feso4 solution, the essence is to remove copper ions, CuSo4 solution can be used to react with iron to generate ferrous sulfate and copper, and then filtered, impurities can be removed and no new impurities are introduced, in line with the principle of impurity removal, the chemical equation of the reaction is: Fe+CuSo4=Feso4+Cu; The reaction is a reaction of a single substance and a compound to generate another element and another compound, which belongs to the displacement reaction To remove Na2CO3 in NaCl, the essence is to remove carbonate ions, and sodium carbonate solution can be used to react with an appropriate amount of dilute hydrochloric acid to generate sodium chloride, water and carbon dioxide, and then evaporate, which can remove impurities and no new impurities are introduced, in line with the principle of impurity removal, the chemical equation of the reaction is:

na2co3+2hcl═2nacl+h2o+co2↑；The reaction does not belong to the compounding, decomposition, and displacement reaction, but belongs to other reaction types Therefore, the answer is: substance A B impurity removal reagent, method C reaction type answer, write the corresponding reaction equation cuo (cu)a high-temperature calcination b o2, heating c hydrochloric acid, evaporation d iron powder, filtration a displacement reaction b chemical reaction c decomposition reaction d other reaction type b; b2cu+o2 △ 2cuo cao（caco3）a；CCACO3 High Temperature cao+co2↑ feso4（cuso4）d；afe+cuso4=feso4+cu． nacl（na2co3）c；dna2co3+2hcl═2nacl+h2o+co2↑

a. Cuo can react with dilute hydrochloric acid to generate copper chloride and water, copper does not react with dilute hydrochloric acid, and then filtered, washed and dried, which can remove impurities and does not introduce new impurities, in line with the principle of impurity removal, so the method taken by the option is correct;

B. KCl is soluble in water, and MMO2 is insoluble in water, so potassium chloride can be obtained by adding water to dissolve, filter and evaporate, and MMO2 is obtained by dissolving, filtering, washing and drying, so the method taken by the option is wrong;

c. The removal of carbon monoxide in carbon dioxide cannot be ignited, because when carbon dioxide (cannot be burned and cannot support combustion) is present in large quantities, a small amount of carbon monoxide will not be burned, and even if it can be burned, oxygen impurities will be introduced, so the method adopted by the option is wrong;

D. HCL can react with excess barium hydroxide solution to generate barium chloride and water, which can remove impurities but introduces new impurities barium hydroxide (excess), which does not meet the principle of impurity removal, so the method adopted by the option is wrong

Therefore, a

If it's just to remove impurities:

Gas impurities are removed without gas, taking advantage of the difference in the properties of the two, carbon dioxide is acidic, so it can be washed with a strong alkali solution. co2+2naoh=na2co3+h2o

Cu (Cuo) can take advantage of the difference in properties between the two, Cuo is an alkaline oxide, Cu is a metal with weaker metal activity than H, and cannot react with dilute sulfuric acid, so copper oxide can be dissolved with dilute sulfuric acid, and copper can be obtained by filtering, washing and drying. cuo+h2so4=cuso4+h2o

If you want to convert impurities:

Carbon dioxide can be converted into carbon monoxide with hot carbon: CO2 + C = 2CO (high temperature) can be used to convert copper oxide into copper through the reducing gas of hydrogen or carbon monoxide: CO+CuO=Cu+CO2 (heating).

First, caustic soda is introduced to remove CO2, and then concentrated sulfuric acid is introduced to dry CO

It is introduced into dilute sulfuric acid, and then filtered and dried.

1. Dry by soda lime.

co2 + cao=caco3

2. Reduction with hydrogen.

Cuo+H2 = Heating = Cu+H2O

The first one removes carbon dioxide through saturated lime water, and the second one is fully reacted with dilute hydrochloric acid and rinsed with clean water and then dried to obtain pure copper.

The first one uses water, and the second one uses sulfuric acid.

To remove Fe in Cu, iron can be removed with dilute sulfuric acid according to different metal activity, because copper and dilute sulfuric acid do not react, and copper can be obtained after filtration; So the answer is: Fe+H2SO4 FeSo4+H2

Concentrated nitric acid can be added, copper can react with concentrated nitric acid, and the iron is passivated when it encounters concentrated nitric acid, thus retaining, and the copper is removed and the iron is retained.

This reaction should be a displacement reaction in high school chemistry, I'm not sure, it should be in the textbook.

The substance in b is the impurity oxygen in the nitrogen gas, and the oxygen is removed when passing through the hot copper, and the copper oxide is a solid and will not be mixed with the nitrogen.

The potassium chloride generated in C is not an impurity, but the mnO2 is a catalyst that does not participate in the reaction, and the potassium chlorate removes the impurities of more Mno2.

Copper oxide can react with dilute sulfuric acid to produce copper sulfate and water, copper does not react with dilute sulfuric acid, can remove impurities and does not introduce new impurities, in line with the principle of impurity removal, the chemical equation of the reaction is: Cuo + H2SO4 = CuSO4 + H2O (reasonable).

To remove Na2CO3 in NaCl solution, the essence is to remove carbonate ions, sodium carbonate solution can be used to react with dilute hydrochloric acid to generate sodium chloride, water and carbon dioxide, which can remove impurities and no new impurities are introduced, in line with the principle of impurity removal, the chemical equation of the reaction is: Na2CO3 + 2HCl 2NaCl + H2O + CO2 (reasonable).

To remove HCl in HNO3, the essence is to remove chloride ions, hydrochloric acid can be used to react with silver nitrate solution to generate silver chloride lake and nitric acid, and then filtered, impurities can be removed and no new impurities are introduced, in line with the principle of impurity removal, the chemical equation of the reaction is: HCl + AGNO3 = AGCL + HNO3

To remove H2SO4 in hydrochloric acid, the essence is to remove sulfate ions, sulfuric acid and barium chloride solution can be used to react to generate barium sulfate precipitate and hydrochloric acid, and then filtered, impurities can be removed and no new impurities are introduced, in line with the principle of impurity removal, the chemical equation of the reaction is: H2SO4 + BACl2 = BaSO4 + 2HCl

Quicklime reacts with water to form calcium hydroxide, and the chemical equation of the reaction is: CaO+H2O Ca(OH)2

Calcium hydroxide reacts with soda ash solution to form calcium carbonate precipitate and sodium hydroxide, and the chemical equation of the reaction is: Ca(OH)2+Na2CO3 CaCO3 +2NaOH

Calcium hydroxide reacts with potassium carbonate solution to form calcium carbonate precipitate and potassium hydroxide, and the chemical equation of the reaction is: Ca(OH)2+K2CO3 CaCO3 +2koH

Therefore, the answer is: cuo+h2so4=cuso4+h2o; ②na2co3+2hcl═2nacl+h2o+co2↑；③hcl+agno3=agcl↓+hno3；④h2so4+bacl2=baso4↓+2hcl．

cao+h2o═ca（oh）2、ca（oh）2+na2co3═caco3↓+2naoh、ca（oh）2+k2co3═caco3↓+2koh．

In cu (cuo) we can add an overabundance of chant.

Dilute sulfuric acid. Then filtered, washed and dried to obtain copper; In NaCl (CaCl, calcium chloride.

. Chloride ions.

Not impurities, calcium ions.

It's impurities, we use.

Carbon talk about acid ions.

Calcium ions can be removed, and the cations in the original substance are.

Sodium ions. So we can join.

Sodium carbonate. Therefore, the answer is: dilute sulfuric acid (containing tan or hydrogen, etc.); Sodium carbonate.

Burning in the air, C+O2==CO2, although some C will reduce Cuo, but the generated Cu will be oxidized and closed by orange cracking oxygen when it continues to burn Wula.

2cuo+c==2cu+co2

2cu+o2==2cuo

The total is still c+O2==CO2