Senior one chemistry questions, please answer the masters, thank you very much!

1.A small amount of solid is taken and put into water, which produces both gas and precipitation.

There must be KhCO3 in gas, only it may produce gas, and it must react with H+ to have gas, so there must be NaHSO4, which can ionize H+, and the precipitation is not analyzed first, and there are more possibilities.

2.Filtration, a small amount of filtrate was added to the AgNO3 solution, and no precipitation was generated.

There must be no CaCl2, so the only cation that can generate precipitated cations is barium ions, so there must be Ba(NO3)2

3.After taking a small amount of filtrate and adding NaOH solution, no precipitation was generated.

Addition of NaOH solution no precipitate and certainly no MgSO4.

Nano3 could not be determined.

NaHSO4 can be seen as a strong monobasic acid.

Therefore, if there is a gas, it can be judged that there must be KhCO3, and another precipitate must be generated.

Since the AGNO3 solution is added, no precipitation is generated, so there are definitely no CL ions.

Add NaOH solution, and there is no precipitation, so there are definitely no mg ions.

Then the precipitation can only be caco3.

Therefore, NaHSO4, KhCO3, and BA(NO3)2 must exist.

CaCl2, MgSO4 certainly don't.

Nano3 has no effect on the above reactions, so it is impossible to be sure.

NaHSO4 can electrically produce hydrogen and sulfate ions in water, and HCO3 combines with H to produce gas. There is precipitation production, and there are BA ions.

There is no precipitation and no chloride ion with silver nitrate.

NaOH is added without precipitation and no mg ions.

There must be no CL ions, and if there were, there would have been precipitation.

According to reaction 2, it can be determined that a cannot be selected, and chlorine will convert ferrous ions into iron ions.

According to reaction 3, it can be judged that b cannot be selected, potassium permanganate will partially convert chloride ions into chlorine gas, and chlorine gas will affect ferrous ions.

D is not chosen, because HCl is not an oxidizing agent and cannot remove iodine ions.

So you can only choose C

Choose C. FeCl3 solution was added to oxidize and remove I- without oxidizing Fe2+ and Cl-.

Chlorine oxidizes ferrous ions to iron ions.

KMno4 oxidizes chloride ions into chlorine gas, and HCI cannot remove iodine ions.

Only FeCl3 can convert iodine ions into iodine and remove them, but has no effect on ferrous ions and chloride ions.

The explanation is as follows; 1 self-disproportionation, 0 to +1, 0 to -1, itself is a reducing agent even if it is an oxidant, and does not need to be used.

2 The realization is the need for a reducing agent.

3. Oxidizer is needed, because it is the lowest price, and it is impossible to act as an oxidant. Oxidizing agents are required.

4 is also the need for oxidant. If it is +2 to 0 on its own, iron and ferric ions cannot coexist, so it is not self-disproportionation. So an oxidizer is needed.

5. Self-disproportionation.

6. Oxidizer is required. In the case of self-disproportionation, 0 to -2 valence, 0 to +4 valence, and S2- and SO32- cannot coexist. So it's not self-disambiguation. Oxidizing agents are required.

Oxidants are required. Therefore, the reactant should be a reducing agent. The valence of the reducing agent increases after the reaction.

You see, that elevation is that. and fifth, disproportionation. Nitrogen dioxide and water reactions are both nitrogen price increases, and there should be no reduction test participation.

So forget it.

Looking at the valence change of the same element, 1 CL2 is 0 valence becomes +1 oxidation reaction, 2 is nitrogen +5 to +4;3 is f from -1 to 0; 4 is from +2 to +3;5 is +4 to +5;6 is 0 to +4, from low price to **, which belongs to the oxidation reaction and requires an oxidant. So all the oxidants are A. D is one less than A, and the real choice should be 1,3,4,6

Both sulfur ions and sulfite ions are mainly reducible, and can coexist under alkaline conditions, while centering reactions occur under acidic conditions. According to the title, the following reaction occurs after adding sulfuric acid to the solution: SO32- +2S2- +6H+ = 3S +3H2O; (If the reaction happens to be complete, the ratio of the amount and concentration of sulfite and sulfur ions is 1:.)

2) Because of the formation of SO2 gas, it can be seen that there is an excess of sulfite, and the excess sulfite undergoes the following reaction: 2H+ +SO32- = SO2 +H2O generates SO2 gas.

Therefore, the ratio of the concentration of the amount of sulfite to sulfur ion is greater than 1:2;

So the answer is C.

c.The sulfur ion and sulfite are neutralized under acidic conditions: 2S +SO6H =3S +3HO

And because there is also so generation, it means that there are too many sulfite ions in the solution. Therefore, the ratio of the two is greater than 1 2

I think I choose B

A: Hno3 has strong oxidizing properties, which will oxidize the generated S02, and at the same time generate low-valent N-containing gases, such as N2, NO2, etc.

C: Dilute hydrochloric acid is volatile, and HCL gas will be mixed in it D: This reaction will generate CaSO4, which has a very low solubility and will adhere to CaSO3 to prevent the reaction from happening further.

AB is oxidized to SO4

d There will be a paste that prevents the reaction so c