Carbonate testing, how to test carbonate ions

Junior high school = = junior high school what theory is not credible...

The junior also says = = copper sulphate does not react with sodium chloride = = actually: Cu(2+) 4Cl(-) = [CuCl4](2-).

This knowledge can only be explained in this way in junior high school.

Test carbonate:

1.BaCl2 solution was added, and hydrochloric acid was added to the filtered pellet. If the white precipitate is dissolved, it proves that the solution contains carbonate ions CO3-.

2.Dilute nitric acid, and then test for carbon dioxide production with barium or calcium ions.

3.Hydrochloric acid can be added first, and the gas produced passes into the magenta solution, if it does not fade, it is passed into the clear lime water, if it becomes turbid, then add calcium chloride solution to the original solution, and if there is a white precipitate, it can be proved that there are carbonate ions in the solution.

4.Barium chloride is added first to produce a white precipitate, and then hydrochloric acid is added to produce a colorless and odorless gas that can make the clarified lime water turbid, which can be proved to be carbonate.

OK. With the continuous addition of acid, colorless and odorless gas begins to be generated, and the gas clarified lime water becomes turbid, indicating that there is carbonate.

Bicarbonate can be excluded, because his phenomenon is different, it is added to the acid and the gas is released immediately, and sulfites and bisulfites can also be excluded.

Are you mistaken, if it is good, it should be added calcium carbonate to generate turbidity, and then acid gas should be added. Because calcium carbonate is poorly soluble in water, while calcium bicarbonate is soluble in water. It is because of this distinction that carbonate is distinguished from bicarbonate.

Although many junior high school theories are contradictory to be studied with university chemistry knowledge, the topics generally do not lead to contradictions. If you are interested, you will naturally have a deeper understanding of chemistry in the future.

Methods for Detecting Carbonate Ions:

1. Add BaCl2 solution, add hydrochloric acid to the filtered precipitate, if the white precipitate is dissolved, it proves that the solution contains carbonate ions.

2. Add dilute nitric acid, and then use barium ions or calcium ions to test whether carbon dioxide is generated, and if there is, it proves that there are carbonate ions.

Carbonic acid (h?).co?) is a binary weak acid with very small ionization constants.

However, it is also considered to be a moderately strong acid, because its acidity is similar to that of phosphoric acid according to the equation (OH)NROM of the acidity of inorganic acid. At room temperature and pressure, the concentration of carbon dioxide saturated solution is about, pH, pka=.