It is known that A, B and C are common substances in middle school chemistry, and they have the foll

1）a,nh3，b,no;cno2;d,o22)a,na,bna2o;c,na2o2;D, O2 chemical equation write it yourself.

3）a,cl2;b,fecl3;cfecl3,d,fe4)a,naoh;b,na2co3;cnahco3;d,co25)a,al3+;b,al(oh)3;c,alo2-;dnaoh6)a,h2o;b,co2;c,co;d,c7)a,ch3ch2oh;b,ch3cho;c,ch3cooh;d,o2

1）4nh3+5o2=4no+6h2o

2) 2Na2O2+2H2O=4NaOH+O23) prevents Fe2+ from being oxidized by oxygen in the air to Fe3+ 2Fe3+ +Fe=3Fe2+

4)co32- +co2+h2o=2(hco3)-5)alo2-

6) b is CO2

7) 2ch3ch2oh+o2—cu, 2ch3cho+2h2o, and then add that the sixth upstairs is wrong, it should be a:mgo,b; co2 c:co d:c

2mgo+c=2mg+co2

The answer should be B, we can use the substitution method, for B answer, A is AlCl3, X is Koh solution, B is Al(OH)3, and C is Naalo2

is chlorine, b is ferric chloride, c is ferrous chloride, and d is iron.

is oxygen, b is carbon dioxide, c is carbon monoxide, d is carbon is sodium hydroxide, b is sodium sulfite, c is sodium bisulfite, d is sulfur dioxide (barium chloride, white precipitate appears).

For ammonia, B for nitric oxide, C for nitrogen dioxide, D for oxygen, as for the problem, you can solve the problem yourself!

(1) 2FeCl2+Cl2===2FeCl32Ca(OH)2+2Cl2===Ca(CLo)2+2Cl2+H2O(2) High temperature.

co2+c===2co

3) Barium chloride and dilute hydrochloric acid.

Phenomenon: After adding barium chloride solution dropwise, a white precipitate is generated, and then dilute hydrochloric acid is dropped, and part of the white precipitate is dissolved and produced with bubbles.

4) D is O2, B is No2, A and C are NH3 and NO, because it is not clear which is NH3 and NO

So there are two cases: 4NH3+7O2===4NO2+6H2O or 2NO+O2===2NO2

A is a black solid, which can be the same as C, Cuo, Fe2O3 and BC, so it may be that C D is a common salt.

So the inference is as follows, a:cb:co

c：co2d：na2co3

e:caco3

na2co3+ca(oh)2=caco3↓+2naoh

A, carbon b is carbon monoxide, c is carbon dioxide, d and e conditions are less clear, it may be bicarbonate and carbonic acid, or calcium carbonate and calcium oxide.

(2) Master the requirements of alkaline gas in secondary school chemistry: NH3. Therefore, A is NH3 According to the transformation diagram, we can know that this is the transformation relationship of nitrogen group elements, and according to the title (B is one of the exhaust gases of the car, it will change color when exposed to air) This sentence can know that B is NO, because NO+O2 NO2 (unbalanced), so C is NO2

The chemical equation for reaction 3 is: NH4 + NO2 = N2 + 2H2O 6NO2 + 8NH3 = 7N2 + 12H2O

The first (4) can be known to contain Na according to (D is a gas that must be reported in the air quality forecast), and according to (the flame color reactions of A, B, and C are all yellow), it is known that it contains Na, and the flame reaction of Na is yellow. Then A is Naoh, B is Na2CO3, C is NaHCO3, B deterioration is to become NaHCO3, that is, to test Na2CO3 and NaHCO3, want to add hydrochloric acid to the solution, if there are bubbles immediately, it means deterioration, because:

In sodium carbonate, a small amount of drops of hydrochloric acid does not bubble at first, and only later.

Na2CO3 + HCl = NaCl + NaHCO3 But in sodium bicarbonate, a small amount of dropwise addition will also foam.

nahco3+hcl=nacl+h2o+co2

The second question is a is NH3, B is NO, C is NO2, and D is O2; The fourth question will not be.

1 d is the most used and most versatile metal This is Fe

The valency of Fe can only be increased, to +2 +3 valence A is a strong oxidant, Cl2 Hno3 and so on can oxidize D to the highest Fe3+

Fe then converts Fe3+ to Fe2+ Fe2+ can also be oxidized to Fe3+ by A

A is a strong oxidant such as Cl2 or Hno3, B is Fe3+ C, Fe2+ D, and Fe

2. Commonly used as a refrigerant is NH3, the lowest valency of N in NH3 can only be increased, and it can be oxidized by oxidants such as O2.

NH3 is oxidized by O2 to NO2 and then to NO2 NO2 is also very oxidizing and can also oxidize NH3 to NO

So A is NH3, B is No, C is No2, and D is O2

3 An important product of the chlor-alkali industry has NAOH so it is speculated that D is NAOH

Because NaOH is oxidized and reduced, its acidity and alkalinity are considered.

Here we can consider the Al triangle, which is the amphoteric that uses Al(OH)3 (which can react with both acids and bases).

Then b should be Al(OH)3, then A is Al3+ C is ALO2- and then A C uses double hydrolysis to reproduce Al(OH)3

So a is Al3+ b is Al(OH)3 C is ALO2 - in fact, Naalo2 and D is Naoh

4. The idea of using the amount of dibasic weak acid to neutralize the base.

A is CO2, B is Na2CO3, C is NaHCO3, and D is Naoh

1;No.

2: A is the refrigerant, so A is NH3, in this case it is continuous oxidation, D is O2, B is N2, and the reaction is O2+N2=NO

3;D is NaOH, A is Al, B is Al(OH)3, C is Naalo2, and the reaction is written according to the chemical formula.

4;D is Cl2, A is Fe, B is FeCl2, C is FeCl3 The answer is that, there may be mistakes, but you think about it.

You'd better divide the language in the question with punctuation, some sentences are not easy to determine the subject, and you don't know whether you are talking about a or b?

If x is elemental (e.g., oxygen), there are many possibilities for a, e.g., a is n2:n2 no no2

A is S:S SO2 SO3

A is NH3: NH3 No NO2 and so on.

The second question is fluoride?

If yes: set fluoride and sulfate to respectively.

Solution: Cl2 reacts with H2 to form HCl gas, which is easily soluble in water to form hydrochloric acid.

So d is hydrochloric acid.

Therefore, considering that A may be a certain metal, combined with the first case of Answer, guess that it is Fe, and then push it down to see if there is a contradiction.

A reacts with D, that is, Fe reacts with hydrochloric acid, and B is FeCl2, note that Fe is +2 valence, and there is still room for oxidation.

B reacts with Cl2, i.e., FeCl2 reacts with Cl2 to form C is FeCl3, and finally, Cl2 reacts with A, i.e., Fe to form FeCl3.

All are smooth, so FE suitability.

3cl2+2fe＝＝2fecl3

Fe+2HCL FeCl2+H2 (Qi Qiqi Song Symbol) ignites. cl2+h2＝＝2hcl

2fecl2+cl2=2fecl3

Here it is! Please criticize and correct.

(1) A is a calcium salt, which is insoluble in water, and there are three elements, and the most common is calcium carbonate. Just guess it first, and it can generally be launched. C+D can generate A, so C and D must contain carbon and calcium respectively, and there is a hint that C is an important substance, which obviously indicates that C is CO2.

Then consider the reaction A---B+C, which is a decomposition reaction, that is, the high-temperature decomposition of calcium carbonate into CaO, CO2

Next, I saw that D+C---A, which is a chemical reaction, and has CO2, and a substance obtained by the reaction of CaO, obviously, it is the legendary test of lime water becoming turbid, D is Ca(OH)2...

2) D is a black solid, and the most learned in middle school are Cuo and Fe3O4. Then it decomposes again, and then it is compounded, and a is h2 (this is a hint from the previous question, right?). When I see H2, I think of the reduction reaction...

Then if you are familiar with the equation, you can write it.

3) A has given sodium bicarbonate and told you that sodium bicarbonate can be decomposed into sodium carbonate, carbon dioxide and water when heated, so.

The reaction of a---b+c has been determined, and then it is trimming.

Seeing the word excess, there is CO2, which is similar to lime water turbidity and clarity, that is, sodium hydroxide and carbon dioxide first react to form sodium carbonate, and then continue to react to generate sodium bicarbonate.