A few chemistry questions, urgent, help solve them!

Question 1: b These substances contain covalent health).

Question 2: These substances are reducible.

Question 3: Yes (group viii is all non-metallic).

Question 4: D first judge that the SO42 labeled 18O will enter the solution according to the dissolution equilibrium.

Later, due to the saturation of the solution, the anhydrous copper sulfate was added, so the anhydrous copper sulfate would crystallize in stream water, so the mass increased and was greater than AG

1. Reaction equation: co+cuo=cu+co2co2naoh=na2co3+h2o

2) One method is calculated by using the carbon dioxide generated by the reaction, and the other is calculated by using the difference method to calculate method 1: since the CO2 generated by CO reduction Cuo is completely absorbed by the NaOH solution and no precipitate and other gases are generated, the weight difference between the NaOH solution before and after the reaction is produced by the reaction (1).

m=80*cuo%=8 (40-30)*100%=80%Method 2: Before and after the reaction (1), the solid mass in the test tube decreases because cuo becomes cu, and the mass of one o atom is reduced.

co+cuo=cu+co2

cuo-cu

m=80*cuo) The fertilizer contains K elements, all of which belong to potassium fertilizer.

2) Because the title knows that 4g samples can generate precipitates, then 2g samples can generate precipitates 3) As can be seen in Figure 2, 4g samples can generate precipitates, and the equation is.

k2so4+bacl2=baso4+2kclm=174*

K2SO4 all, the fertilizer complies with the label instructions.

4) The quality of potassium provided by the chemical fertilizer is the quality of the potassium contained in the chemical fertilizer.

m(k+) = mass of chemical fertilizer * mass fraction of k2SO4 in chemical fertilizer * mass fraction of K element in k2SO4.

W: Sodium, X: Aluminum, Y: Sulfur, Z: Chlorine.

1)al(oh)3+naoh=naalo2+2h2o2)na2s

3)so?+cl?+2h?

o=h?so?+2HCLHClLop + SO2 + H2O == HCL+ H2SO4 Detailed Answer:

1) From the first piece of information, our first reaction wx is acid and base, but the title says that wx is a metal element, so our first reaction is wrong, and then think that the most ** oxide corresponding hydrate of the two metal elements can react like this, then there is only amphoteric oxide alumina and another strong base, and the atomic number of x is larger than w, so we can know that w is sodium, and x is aluminum.

2) Since we have deduced that WX is sodium and aluminum, and the atomic number of YZ is larger than them, then the remaining scrap metal elements in this cycle are, silicon, phosphorus, sulfur, chlorine, etc., since WY can form W2Y, then we clearly know that Y is chlorine and W2Y is Na2S

3) If we already know that y is sulfur, then z can only be chlorine.

Very detailed Oh I hope it helps you, I hope you too! ~

We have learned how to produce oxygen in the laboratory, please ask the following questions. (1) When selecting the reactants for the preparation of oxygen, the first thing should be selected from the substances containing oxygen atoms. (2) Xiao Ming knows by checking the information:

In addition to hydrogen peroxide solution that can produce oxygen, the following methods can produce oxygen: Electrolysis of water 2H2O=2H2+O2 Heating potassium permanganate solid: 2kmNO4=K2mNO4+Mno2+O2 Chemical reaction equation) Heating mercury oxide:

2 hgo=2hg+o2 chemical reaction equation) Please name two reasons why laboratories are not inclined to use the above methods to produce oxygen: Mercury is toxic Water electrolysis experiments are complex and energy consumes energy Heating potassium permanganate to produce oxygen Oxygen yield is low cost and high 3) The diagram on the right is a schematic diagram of the device for producing oxygen from hydrogen peroxide solution and manganese dioxide. To check whether the generator device is airtight, it is usually necessary to insert the catheter orifice into the water and then hold the outer wall of the Erlenmeyer flask with both hands to observe whether air bubbles are formed at the catheter orifice.

Please analyze the basis for this practice (explained from the point of view of particles): The gas in the bottle is heated and expands to produce bubbles 4) The separating funnel is used in the generating device, compared with the long-necked funnel, its advantage is that the separating funnel can control the dropping acceleration and the gas in the bottle will not run out of the funnel Using the long-necked funnel, the lower nozzle does not extend below the liquid level, which may cause oxygen to leak from the long-necked funnel 5) Oxygen is produced with hydrogen peroxide solution and manganese dioxide, and its chemical equation is 2H2O2=2H2O+O2 where the role of manganese dioxide is to catalyst manganese dioxide After the experiment, the experimental operation of manganese dioxide is to filter to obtain manganese dioxide

1) Oxygen.

2) 2kmNO4 heats K2mNO4 mNO2 O2 2Hgo= =2Hg+O2

3) Hold the Erlenmeyer flask, so that the gas in the bottle is heated, the particle movement rate increases, the interval becomes larger, the gas volume expands, and it can escape from the catheter mouth.

4) Not only can the air reaction be carried out or not, but also the speed of the reaction can be controlled.

Allow the generated oxygen to escape from the long-neck funnel along the lower end of the nozzle.

5) 2H2O2 = MNO2 = 2H2O+O2 catalyst. Filtration.

Hope, although there is no diagram, but according to the knowledge points and the characteristics of chemical instruments, it can still be answered.

Oxygen. KMNO4==Heating==K2MNO4+MNO2+O2 2HGO (Heating)2HG+O2

1.The reaction conditions are required to be high 2The reaction is energy-intensive.

The higher the temperature, the faster the particles move.

You can control the amount of substance you add.

No oxygen is collected in the gas collection cylinder.

2H2O2==Mno2==2H2O+O2 catalysis. Filtration.

ccuso4+fe===cu+feso4

The relative molecular mass of FeSo4 is less than.

Relative molecular weight of CuSO4.

So the solution mass of the solution is reduced.

Select c The amount of iron of a certain substance is replaced with the amount of copper of the same substance, but because the relative molecular mass of copper is greater than that of iron, the solution is reduced.

AB both produces hydrogen, but increases the mass of iron, so the mass of the solution increases.

d is also an increase.

No, the obvious answer is * 8 = mol.

s2- to s6+, loss of 8 electrons; N5+ to N4+, 1 electron is obtained.

There is a concentrated nitric acid in the reaction.

b According to the conservation of electrons s2- to s6+, 8 electrons are lost; N5+ to N4+, 1 electron is obtained.

So s:n=8:1, s=8n, i.e., the restored.

Answer: No answer.

It should be Moore.

The nitric acid that participates in the reaction is.