There is a white crystal crystals crystallized from a northern salt lake

If you add nitric acid to the last one, add agno3 first, and the rest of the substance is:

Suppose sodium carbonate, sodium sulfate, sodium chloride have): agcl, nano3, ag2co3, na2so4, agso4

There is already a troubling problem here, the resulting AGSO4 is slightly soluble in water, which is not good for your later judgment. Even if you leave it alone, and then you add bano3, you generate baso4. At this point, there are two white precipitates in the solution that are insoluble in nitric acid:

AGCL and BaSO4. Finally, you add nitric acid, and some of the precipitate is insoluble, so you can't tell whether there are both chloride ions and sulfate ions or only one.

If you add nitric acid first, then barium nitrate, silver nitrate solution, if there are both chloride ions and sulfate ions, you will see an increase in precipitation after adding the silver nitrate solution. Not the other way around.

1.Add water to dissolve.

- Make a solution.

3.Add enough nitric acid.

- There is a gas generation to prove that there is sodium carbonate.

2.If there is a sufficient amount of barium nitrate solution.

- There is a precipitate to produce proof of sodium sulfate.

4.Add the silver nitrate solution.

There is a precipitate to produce evidence of sodium chloride.

Note: -- Add nitric acid before adding barium sulfate or silver nitrate to exclude carbonate ions, so the 3rd is before the 24th.

- Silver nitrate can react with sodium chloride to form a precipitate, and can also react with sodium sulfate to form a silver sulfate precipitate, silver sulfate is slightly soluble in water, so before adding silver nitrate, barium nitrate is added to detect sodium sulfate, so the second must be before the fourth.

1324 is right.

1.Dissolve. 3.+ Nitric acid, where there is gas, there is sodium carbonate.

2.+ Barium nitrate, with white precipitate, there is sodium sulfate.

4.+ Silver nitrate, with white precipitate, there is sodium chloride.

If it is 1423, add silver nitrate first, and there will be a white precipitate, and it is impossible to prove whether there is sodium chloride.

1 No problem. 4. Silver chloride and silver sulfate precipitation Silver ions will also react with carbonate.

3. Verify the carbonate.

2. Verify the sulfate (acidic insoluble precipitate) and remove the sulfate at the same time to prevent the impact on the chloride ion test.

4. Chloride ions.

A. Because salt is edible, but not salt can be eaten, so A is wrong.

B. Because salt is the common name of sodium chloride, salt is a general term for a class of compounds composed of metal ions and acid ions Table salt is a kind of salt, and some salts are insoluble in water, so B is wrong

C. Because salt is not a white crystal, like copper sulfate solid is blue, so C is wrong, D, because the concept of salt knows, salt is a general term for a class of compounds composed of metal ions and acid ions, so D is right. Therefore, choose D

First add water to dissolve the sample into a solution, and then add a sufficient amount of nitric acid, nitric acid and sodium carbonate reaction can produce carbon dioxide gas, so add nitric acid, there is gas generated, indicating that it contains sodium carbonate, and the sodium carbonate is removed, in addition to barium nitrate, because barium nitrate reacts with sodium sulfate to form a white precipitate barium sulfate insoluble in nitric acid, so after adding barium nitrate, there is a white precipitate generated, indicating that it contains sodium sulfate, and finally silver nitrate solution is added, silver nitrate reacts with sodium chloride to produce silver chloride white precipitate, and insoluble in nitric acid, Therefore, the addition of silver nitrate can identify whether it contains sodium chloride; So the order is:

Therefore, b

First add water to dissolve the sample into a solution, and then add a sufficient amount of nitric acid, nitric acid and sodium carbonate reaction can produce carbon dioxide gas, so add nitric acid, there is gas generated, indicating that it contains sodium carbonate, and the sodium carbonate is removed, in addition to barium nitrate, because barium nitrate and sodium sulfate react to form a white precipitate barium sulfate that does not block the macro dissolved in nitric acid, so after adding barium nitrate, there is a white precipitate brochure generated, indicating that it contains sodium sulfate, and finally add silver nitrate solution, silver nitrate reacts with sodium chloride to produce silver chloride white precipitation, It is insoluble in nitric acid, so the addition of lead oak silver nitrate can identify whether it contains sodium chloride; So the order is:

Therefore, b

Due to the different influencing factors of the two situations, the precipitation crystals in different seasons are different In summer, due to the large evaporation and water loss, the solubility is not affected by temperature or plexicity, so the precipitation of sodium chloride is not greatly affected by temperature and in winter, due to the existence of large temperature difference, the solubility is greatly affected by temperature

Answer: Because the solubility of soda ash decreases with the decrease of temperature and is greatly affected by temperature, while the solubility of sodium chloride is very small by temperature, soda ash crystals will be precipitated in winter due to the low temperature of the leased fiber; The reason for drying salt in summer is that the solubility of sodium chloride is very low by the temperature, and the evaporation of water can lead to the precipitation of crystals

Due to the different influencing factors of the two conditions, the precipitation crystals in different seasons are different In summer, due to the large evaporation and water loss, the solubility is not greatly affected by the temperature of sodium chloride precipitation, and in winter, due to the existence of large temperature difference, the solubility is greatly affected by temperature

Answer: Because the solubility of soda ash decreases with the decrease of temperature and is greatly affected by temperature, while the solubility of sodium chloride is very small by temperature, soda ash crystals will be precipitated due to low temperature in winter; The reason for drying salt in summer is that the solubility of sodium chloride is very low by temperature, and the evaporation of water can lead to the precipitation of crystals

First add water to dissolve the sample into a solution, and then add a sufficient amount of nitric acid, nitric acid and sodium carbonate reaction can produce carbon dioxide gas, so add nitric acid, there is gas generated, indicating that it contains sodium carbonate, and the sodium carbonate is removed, in addition to barium nitrate, because barium nitrate reacts with sodium sulfate to form a white precipitate barium sulfate insoluble in nitric acid, so after adding barium nitrate, there is a white precipitate generated, indicating that it contains sodium sulfate, and finally silver nitrate solution is added, silver nitrate reacts with sodium chloride to produce silver chloride white precipitate, and insoluble in nitric acid, Therefore, the addition of silver nitrate can identify whether it contains sodium chloride; So the order is:

Therefore, b