Is it a mixture or a compound, and ask why Fe3C is not a solid solution

The distinction is simple, solid solutions cannot be represented by chemical formulas, and compounds can be represented by chemical formulas. Compounds have a fixed ratio, such as Fe3C which is three to one. The solid solution phase A, Fe and C are disproportionate and have maximum solubility.

Ferric tetroxide is a ferrite i.e., Fe(FeO2)2

Ferric oxide can be regarded as a compound composed of FeO and Fe2O3, which can be expressed as FeO·Fe2O3, but cannot be said to be a mixture of FeO and Fe2O3, it is a pure substance.

Fe2O3 iron oxide is not a mixture.

A mixture is a mixture of a variety of substances (elemental or compoundy) that are pure. The mixture does not have a chemical formula. There is no fixed composition and properties, and each element or compound retains its original properties.

In the mixture, a variety of substances contained in it do not react with each other and still maintain the original chemical properties.

As long as you can write a chemical formula, it is pure.

1）fe2o3+6h+=2fe3++3h2o ； cu+2fe3+=2fe2++cu2+

2) Cu, Fe2O3, and hand-held SiO2; sio2+2naoh=na2sio3+h2o

3) Washing the Absolute Potato family M(Fe2O3):m(Cu):M(SiO2)=:3.

Fe + 2HCl = FeCl2 + H2 or Fe + H2SO4 = FeSO4 + H2If there are bubbles generated, then the hydrogen will volatilize until there are no bubbles, and there is no FeCl2, how to get copper after filtration?

Answer: Fe becomes FeCl2, FeCl2 is soluble in water, whereas copper is insoluble in water.

Therefore, copper is the precipitate, and the precipitate obtained by filtration is copper, and FeCl2 flows through the filter paper and flows into the filtrate.

fe + cucl2 = fecl2 + cu

In order to add enough iron powder to the mixture until no red substance is formed, it is a FeCl2 solution after filtration, why is there no red substance limb and formation?

Answer: Strictly speaking, it should be said that the red substance is no longer produced (emphasis on "no more").As far as Yindan is concerned, CuCl2 is completely reactive, and Cu. is generated

Cu is insoluble in water, the filtration is left on the filter paper, and FeCl2 flows into the filtrate.

According to the inscription, find out the breakthrough "it reacts with clarified lime water to form a white precipitate", "yellow solution d must contain iron ions", "mixture A adds sodium hydroxide solution to generate gas that turns litmus solution blue", then it is speculated to be alkaline gas ammonia According to the dilution of sulfuric acid in mixture A to produce gas B, it reacts with clarified lime water to form a white precipitate, then it can be seen that the gas is carbon dioxide produced by the reaction of carbonate ions and hydrochloric acid, and it must contain BaCO3

Yellow solution D must contain iron ions, then FeCl3 in the original mixture cannot be determined

With fe (NO3

the presence of the situation; Mixture A is added to a solution of sodium hydroxide to produce a gas that turns the litmus solution blue, which is presumed to be NH4 in the solid

NO3 can react with sodium hydroxide to produce ammonia, then:

1) The chemical formula of gas E is NH3

2) In mixture A, the substance that is definitely present is BAC3

nh4no3

3) The metal cation present in solution G is (write the ion symbol) Na+

4) In the solid mixture, among the above four substances, it is not certain that the substance that exists is (write the chemical formula) FeCl3

fe（no3

The reason for this conclusion is that D is a yellow solution, and Fe3+ must be present in this solution

in fecl3

With fe (NO3

The solution contains Fe3+

And none of them react with dilute sulfuric acid, so it is not possible to determine FeCl3 in the original mixture

With fe (NO3

the presence of the situation;

5) To determine the existence of the substance in (4), take the colorless solution g for further experiments, please briefly explain the experimental operation steps, the phenomenon and the conclusion Take a small amount of solution g in the test tube, add a little silver nitrate solution, if there is a white precipitate, it means that the sample must contain FeCl3

May contain Fe (NO3

If there is no white precipitate, the sample does not contain FeCl3

It must contain Fe(NO3

So the answer is: (1) NH3

2）baco3

nh4no3

3）na+4）fecl3

fe（no3

Since D is a yellow solution, Fe3+ must be present in this solution

in fecl3

With fe (NO3

The solution contains Fe3+

And none of them react with dilute sulfuric acid, so it is not possible to determine FeCl3 in the original mixture

With fe (NO3

the presence of the situation;

5) Take a small amount of denier solution g into the test tube, add a little silver nitrate solution, if there is a white precipitate, it means that the sample must contain FeCl3

May contain Fe (NO3

If there is no white precipitate, the sample does not contain FeCl3

It must contain Fe(NO3

A FeCl3 solution and Fe(OH)3 colloids are homogeneous.

1. Transparent and stable dispersion system, but the FeCl3 solution is light yellow, and the ferric hydroxide colloid is reddish-brown, so A is wrong;

b The diameter of colloidal particles is between 1-100 nm, the particle diameter of the solution is less than 1 nm, and the sub-diameter of the turbidity solution is greater than 100 nm, so the particle size of iron hydroxide colloidal colloidal particles is 1-100 nm, and the particle size of FeCl3 solution is less than 1 nm, so B is wrong;

c ferric hydroxide colloids have Tyndall effect, ferric chloride solution does not have Tyndall effect, and the Tyndall effect can be used to distinguish colloids from solutions, so c is correct;

d The ferric chloride solution does not have the Tyndall effect, so d is wrong;

Therefore, C

After adding water, a solution and a precipitate are formed, and only barium chloride can be dissolved in water in the given substance, and the rest of the substances cannot react with it, so it must contain barium chloride, and barium chloride enters the solution and the excess hydrochloric acid is added to the precipitate to obtain gas after heating, only calcium carbonate can get gas in a given substance, and the gas is carbon dioxide Iron hydroxide and iron oxide can react with hydrochloric acid to finally get a yellow solution, so it is impossible to judge which of the two substances exists or both

1) Iron oxide, iron hydroxide, calcium carbonate, copper are insoluble in water, and barium chloride is soluble in water, so filtrate A contains barium chloride, according to the conditions of metathesis reaction, so the precipitate C is barium sulfate, so the answer is: baso4

Only calcium carbonate will react with hydrochloric acid to form gas in the precipitation, so there must be calcium carbonate in precipitation B, and gas E is carbon dioxide, so the answer is: CO2

2) According to the derivation in (1), we know that there must be calcium carbonate and barium chloride, which are all dissolved after precipitation and sulfuric acid are added, so there must be no copper, so the answer is: BaCl2, CaCO3, Cu

3) According to the yellow color of iron ions in solution, which is formed by adding excess dilute hydrochloric acid, the answer is: FeCl3

4) Calcium carbonate reacts with hydrochloric acid to form calcium chloride, water and carbon dioxide, so the answer is: CaCO3+2HCl=CaCl2+H2O+CO2

A D should be chosen for this question

There is no obvious phenomenon when FeCl3 solution is dropped into hydrochloric acid, and Fe(OH)3 colloids dropping hydrochloric acid will first cause polymerization and precipitation due to the action of negative charge, and then the amount of hydrochloric acid will be large and the acid-base neutralization reaction will occur with iron hydroxide.

The colloid (iron hydroxide) meets the electrolyte (hydrochloric acid) and converges and settles (iron hydroxide precipitation), and the continuous dropwise addition of hydrochloric acid is the iron hydroxide precipitation and hydrochloric acid acid-base neutralization reaction.