Grade 9 Chemistry Speculative Class Urgent

Answer: This title is a block diagram material inference problem, the key to complete this kind of problem is to find the breakthrough point of the solution, according to the key to the narrative, as well as the nature of the substance and the reaction between the substance, make a judgment, A is the main component of magnetite, then A is ferric oxide, B and D are gases, then B may be carbon monoxide, D may be carbon dioxide, the generated C is iron, J is a green powdery solid, then J may be basic copper carbonate, and the heat energy decomposes to produce water, copper oxide and carbon dioxide, F is a red solid element, heating can generate I, then F may be copper, I may be copper oxide, H may be water, E can generate water by ignition, then E may be hydrochloric acid, reagent A may be hydrochloric acid, iron can react with reagent B to form copper, then B may be copper sulfate, G is a white solid insoluble in water, then G may be calcium carbonate, carbon dioxide can react with C to form calcium carbonate, then C may be calcium hydroxide, substitute into the block diagram, reasonable inference Answer: Solution:

1) A is the main component of magnetite, then A is ferric oxide, B and D are gases, then B may be carbon monoxide, D may be carbon dioxide, C is iron, J is a green powdery solid, then J may be basic copper carbonate, and the heat can decompose to form water, copper oxide and carbon dioxide, F is a red solid element, heating can produce I, then F may be copper, I may be copper oxide, H may be water, E can be ignition to produce water, then E may be hydrogen, and Reagent A may be hydrochloric acid, Iron can react with reagent B to form copper, then B may be copper sulfate, G is a white solid insoluble in water, then G may be calcium carbonate, carbon dioxide can react with C to form calcium carbonate, then C may be calcium hydroxide, so the answer to this question is: H2, Cu;

2) Carbon monoxide can react with ferric oxide to produce carbon dioxide and iron, so the answer to this question is: Fe3O4+4Co high temperature 3fe+4co2；

3) Carbon dioxide reacts with calcium hydroxide to form calcium carbonate precipitate and water, so the answer to this question is: CO2 + Ca(OH)2 CaCO3 + H2O;

4) Basic copper carbonate can be decomposed by heat to form copper oxide, water and carbon dioxide, so the answer to this question is: Cu2(OH)2CO3 2CuO+H2O+CO2 Comments: This title is a block diagram substance inference question, to complete this kind of question, you can find the breakthrough of solving the problem according to the information provided by the question stem, combined with the block diagram, and directly obtain the chemical formula of the substance, and then deduce or reverse or from both sides to the middle to derive the chemical formula of other substances

Solution: (1) A is the main component of magnetite, then A is ferric oxide, B and D are gases, then B may be carbon monoxide, D may be carbon dioxide, C generated is iron, J is a green powdery solid, then J may be basic copper carbonate, and the heating energy can decompose to form water, copper oxide and carbon dioxide, F is a red solid element, heating can generate I, then F may be copper, I may be copper oxide, H may be water, E can be ignition to produce water, then E may be hydrogen, reagent A may be hydrochloric acid, Iron can react with reagent B to form copper, then B may be copper sulfate, G is a white solid insoluble in water, then G may be calcium carbonate, carbon dioxide can react with C to form calcium carbonate, then C may be calcium hydroxide, so the answer to this question is: H2, Cu;

2) Carbon monoxide can react with ferric oxide to produce carbon dioxide and iron, so the answer to this question is: Fe3O4+4Co high temperature 3fe+4co2；

3) Carbon dioxide reacts with calcium hydroxide to form calcium carbonate precipitate and water, so the answer to this question is: CO2 + Ca(OH)2 CaCO3 + H2O;

4) Basic copper carbonate can be decomposed by heat to produce copper oxide, water and carbon dioxide, so the answer to this question is: Cu2(OH)2CO3 2CuO+H2O+CO2

1) Observe the sample, the sample with the vertical color of blue and old is copper sulfate pentahydrate.

2) Use the four test tubes of Zhuzen to take a small amount of the remaining four samples and add (hydrochloric acid) solution to each. --It can also be a sulfuric acid solution.

The sample that forms the blue solution is (cuso4); - Only its aqueous solution is blue.

Samples that form a colorless solution without gas formation are (NaCl) and continue the experiment with samples with gas formation. --It may be Na2CO3, both of which generate CO2 gas.

3) Weigh a certain amount of samples generated by gas in the experiment (2) and heat them, cool them and weigh them again. The samples with reduced mass were (; - Decomposes and loses crystalline water.

The sample with no change in mass is (Na2CO3).

1) Observe the sample, the blue sample is copper sulfate pentahydrate.

2) Take a small amount of the remaining four samples with four test tubes, and add (dilute salt bucket sail acid) solution to each. The samples that form the blue solution are (copper sulfate); Samples with no gas formation and no dry color solution are (sodium chloride) and continue the experiment on the sample with gas formation.

3) Weigh a certain amount of samples generated by gas in the experiment (2) and heat them, cool them and weigh them again. The samples with reduced mass were (sodium carbonate decahydrate); The sample with the same mass is (sodium carbonate).

Sodium carbonate decahydrate is heated and decomposed into sodium carbonate and water, and water evaporates).

H2SO4 copper sulphate.

Sodium chloride. Sodium carbonate decahydrate.

Sodium carbonate.

The title says that phenolphthalein or litmus solution was added dropwise to it. That is to say, one of them may be added dropwise to the solution, and from the second question, it can be known that when you add A, the solution changes from colorless to yellow, and there is no gas, then A is iron oxide, only Fe ions are yellow, and only acid reacts with it in the question.

(1) The common name of G is (baking soda) The chemical formula of X is NaOH (2) Mars shines and emits heat, and black molten matter splashes on the bottom of the bottle (3Fe + 2O2 = ignition = Fe3O4).

3) The conditions of the b reaction are (heating).

4）③fe+h2so4=feso4+h2↑④co2+ca(oh)2=caco3↓+h2o

5) increase the conformance (NaOH will deliquescent, and react with CO2 in the air) (6) Conclusion: Carbonate can react with acid to form CO2

I can't see the diagram clearly, so please make the diagram clearer.

1. G is baking soda; x is naoh; 2. The combustion phenomenon in oxygen is sparks, emitting a large amount of heat, and black solids are generated;

c: carbon dioxide; g: is sodium bicarbonate: f: is sodium carbonate 3, b The condition for the reaction to occur is heating;

4、fe+h2so4=h2+feso4；co2+ca(oh)2=caco3+h2o

5. Enlargement; Compliance with conservation of mass; 6. It is a metathesis reaction to generate carbon dioxide and water.

Na2O2 mass = 975*80% = 780g2CO2 + 2Na2O2 == 2Na2CO3 + O2156 32

780g m156/780 = 32/m

m = 160g

So 160 grams of oxygen can be generated.

Solution: Let the mass of oxygen generated be x

975g*80%=780g

2na2o2+2co2==2na2co3+o2↑156 32

780g x

156/32 = 780g/x

x=160g

A: Produces 160g of oxygen.

Steps First, set the unknown quantity.

The mass of the pure substance participating in the reaction is calculated.

List chemical equations.

Write the relative molecular mass (considering the coefficient) below the corresponding substance, and the known and unknown quantities in the following line.

Column-proportional solution to the root of the question.

A: H2O2 B: H2O C: Fe3O4 D: CO2 E: Co A: Zhiqing O2 B: H2 C: Fe

A->A+B: 2H2O2==2H2O+O2A->E: Only open 2C+O2=2Co

A->C: 3Fe+2O2=Fe3O4