Our chemistry teacher said that CO2 is passed through the Na2SiO3 solution, and acid salts are forme

In fact, it is the principle of strong acid to weak acid, orthosilicic acid H4SiO4 is easy to lose water to generate silicic acid H2SiO3, silicic acid is weaker than carbonic acid, but stronger than bicarbonate, the key is not too much.

If the ionization constant of the second step of carbonic acid is greater than the ionization constant of the first step of silicic acid, it may form a positive salt, depending on how much c02, if the ionization constant of the second step of carbonic acid is less than the ionization constant of the first step of silicic acid, it can only generate acid salt.

If orthosilicic acid is generated, there must be too much carbon dioxide, so it can only be the acid salt NaHCO3

Depending on the amount of CO2, when the amount of CO2 is small, NA2CO3 is generated, and when the amount of CO2 is large, it is NAHCO3.

na2co3+co2+h2o=2nahco3

I think what you teachers want to emphasize is the order of acidity, H2CO3 > H2SiO3 > HCO3.

Actually, you don't have to, and the order is wrong.

At the high school level, the only order to be clear and emphasized is that H2CO3 > phenol > HCO3-

Therefore, when CO2 is introduced into the sodium phenol solution, no matter how much CO2 is or how little CO2 is, only NaHCO3 can be generated

In addition, it is also necessary to know that the acidity of HCl, H2SiO3 and Al(OH)3 is weaker than that of H2CO3, so the precipitation of CO2 can be produced when CO2 is introduced into Ca(ClO)2, Na2SiO3 and Naalo2 solutions, but it is generally believed that less CO2 generates Na2CO3 and more CO2

If it is true, I think the acidity of H2SiO3 should be weaker than that of HCO3-, after all, H2SiO3 is an insoluble precipitate, and in the same way, Al(OH)3 is also a precipitate, so if CO2 is introduced into the solution of Na2SiO3 and Naalo2, it should be a small amount of CO2 to form Na2CO3, and NaHCO3 is generated in excess

If you are a sophomore in high school and learn the principles of chemical reactions, you will find that HCro is slightly more acidic than HCO3, so if you introduce CO2 into Naclo, you should only be able to produce NaHCO3.

Your teacher is right, HCO3- is weaker acidic than H2SiO3, so Na2CO3 is not produced;

In fact, these are all just an experiment: adding sodium bicarbonate to the sodium silicate solution will not generate silicic acid precipitate and sodium carbonate.

If so, then sodium carbonate will be formed by passing a small amount of CO2 in Na2SiO3 solution. Otherwise, sodium bicarbonate will be generated.

But the fact is that sodium silicate solution does not react with sodium bicarbonate, so no matter how much CO2 you pass, acid salts will always be generated.

Na2SiO3+CO2+3H2O=H4SiO4 +Na2CO3 I think it's this, but what I didn't check the information was the feeling.

Look downstairs.

All good! It depends on the amount of CO2, when the amount of CO2 is small, it is NA2CO3, and when the amount of CO2 is large, it is NAHCO3.

Because: Na2CO3 + CO2 + H2O = 2NaHCO3

I think if there is a small amount of carbon dioxide, sodium carbonate will be generated.

This reaction is related to the relative amount of hydrochloric acid and sodium carbonate.

When sodium carbonate reacts with dilute hydrochloric acid, if there is an excess of sodium carbonate (a small amount of hydrochloric acid), then its chemical equation is:

When Na2CO3+HCl=NaCl+NaHCO3 sodium carbonate reacts with dilute hydrochloric acid, if there is an excess of hydrochloric acid (a small amount of sodium carbonate), then its chemical equation is:

Na2CO3+2HCl=2NaCl+CO2+H2OMany chemical reactions are related to the amount of substances participating in the reaction, for example: carbon is burned in sufficient oxygen to form CO2; And if there is not enough oxygen, toxic CO is formed.

Because sodium carbonate is soluble in water, the contact between sodium carbonate and hydrochloric acid is very sufficient, and the reaction rate is too fast to be collected, so the laboratory generally uses dilute hydrochloric acid and water-insoluble marble to react to prepare CO2.

Carbon dioxide is a colorless, odorless, and odorless gas at room temperature. The chemical formula is co, formula amount, one of the carbon oxides, commonly known as carbonic acid, also known as carbonic anhydride or carbonic anhydride. At room temperature, it is a colorless and odorless gas, slightly denser than air, soluble in water (1 volume Ho can dissolve 1 volume CO), and produces carbonic acid.

Solid carbon dioxide, commonly known as dry ice, can absorb a lot of heat during sublimation, so it is used as a refrigerant, such as artificial rainfall, and is also often used in stage art to create smoke (dry ice sublimation absorbs heat, and liquidates water vapor in air).

Hydrochloric acid itself is volatile, which affects the purity of the prepared CO2 gas.

HCl is volatile and can affect purity.

This reaction is more violent than that of hydrochloric acid and sodium carbonate.

It's wrong, it's more violent than hydrochloric acid and calcium carbonate, sodium carbonate is mainly a powder, and the reaction is relatively violent.

Categories: Education Science >> Admission >> College Entrance Examination Problem Description:

CO2 reacts with water to form H2CO3

It ionizes in the form of H+ and CO32-.

Why is naco3 generated instead of nahco3?

Analysis: You can understand it this way:

co2+h2o=h2co3；

h2co3+naoh=nahco3+h2o; h2co3+2naoh=na2co3+2h2o

It is also said that when CO2 is excessive, the product is NaHCO3; When there is an excess of NaOH, the product is Na2CO3;

Therefore, when CO2 is introduced into the NaOH solution, at the beginning, when the NaOH is excessive, the product is Na2CO3; As CO2 increases, it becomes NAHCO3. (Actually, Na2CO3+CO2+H2O=NaHCO3).

The water stuffiness reacts with CO2 to form carbonic acid.

Carbonic acid is stronger than silicic acid.

Therefore, polysilicic acid is generated.

Chemical reaction formula.

na2sio3+co2+h2o=h2sio3↓+na2co3

The initial substance of the reaction between Na2SiO3 and CO2,H2O is H4SiO4, but it is unstable and volatile aquatic H2SiO3

Na2SiO3+CO2+2H2O===Na2CO3+H4SiO4 (strong acid to weak acid).

Because h4sio4===h2sio3+h2o, sometimes we can also write the reaction like this:

The amount of Na2SiO3+CO2+H2O===Na2CO3+H2SiO3 only affects the production of salt. For example, if there is too much carbon dioxide, NaHCO3 is produced

na2co3+co2+h2o===2nahco3

The equation of CO2, H2O and Na2O2 reaction is tricky for many students, and it is basically written by rote memorization, but the good times are short-lived, and they will soon forget! So what to do? Teacher Qianlong created an original method to share with dear students, welcome students to be serious!