Why is Na2CO3 NaHCO3 solution alkaline?

The main reason is that the anions of salt are hydrolyzed in water to cause its process alkaline, generally the acid base of weak acid can form strong alkali salt, weak alkali is generally acid salt, can not be said to be strong acid because the general acidity is very weak.

The figure below shows the ionic formula of the hydrolysis of the two:

Sodium carbonate and sodium bicarbonate are hydrolyzed in water to produce less sodium hydroxide, so their aqueous solutions are alkaline. The hydrolysis of substances is learned in high school chemistry.

The general method of judging the acidity and alkalinity of the salt solution is: strong acid and weak alkali salt, that is, sulfuric acid, hydrochloric acid, nitric acid and copper hydroxide, iron hydroxide and other insoluble alkalis to form a salt (such as copper sulfate, iron chloride, silver nitrate, etc.) solution is acidic; Strong alkali and weak salts, that is, strong bases such as sodium hydroxide, potassium hydroxide, barium hydroxide and weak acids such as carbonic acid and hydrosulfuric acid (such as sodium carbonate, potassium carbonate, etc.) are alkaline; The solution of strong acid, strong alkali salt and weak acid and weak alkali salt is generally neutral.

In OH, but the presence of OH is not necessarily alkaline.

How to judge the acidity and alkalinity of an alkaline solution that must be salted? As follows:

OH is ionized after the solution is dissolved in water, for example, after Na2CO3 is dissolved in water, H- in the water combines with CO3- to form CO2 gas; Sodium ions can only combine with OH- in water to produce NAOH, and NAOH is easy to ionize, that is, ionization out of OH- makes the solution alkaline;

The same is true for H-, such as acetic acid (CH3COOH), although it is a weak acid and is not easy to ionize, it will still ionize acetate (CH3COO-) and H- when dissolved in water, it is acidic;

There must be OH- in alkaline solutions, because alkaline solutions are defined by it, and OH can be obtained after hydrolysis of CO3 ions in Na2CO3--。 The acidity and alkalinity of salt is judged by whether it is H+ or OH- formed by hydrolysis.

Hydroxide ions are present in any solution;

Hydroxide ions are produced by the ionization of water, only because of the difference in concentration in solution;

The acidity and alkalinity of the salt solution depends on the contrast between the acidity and alkalinity of the anion and cation: take sodium carbonate as an example, the combination of sodium ions and hydroxide ions forms a strong alkali of sodium hydroxide, and the combination of carbonate ions and hydrogen ions forms a weak acid of carbonate, so the solution is alkaline (of course, the combination is what we assume, but it does not exist, and the acid will be neutralized in the alkali).

It can be understood more simply, the salt solution formed by strong alkali and weak acid becomes alkaline, and the salt solution formed by strong acid and weak alkali becomes acidic. NaOH is a strong base and H2CO3 is a weak acid, so it is alkaline. Then write the ionization formula of salt and the ionization formula of water, which can be seen.

Hydrolysis is alkaline, carbonate ions combine with hydrogen ions produced by water ionization, and destroy the ionization balance of water, because the concentration of hydroxide ions in the solution is greater than the concentration of hydrogen ions, so it is alkaline. The same goes for sodium bicarbonate.

co3+h2o===hco3+oh

hco3+h20===h2co3+oh

Hydrolysis is alkaline.

An alkaline solution does not have to be a base.

Kenneng is obtained by hydrolysis of salt solution.

You write the equation for the hydrolysis of the salt solution.

Of course, you have to use ionization.

Carbonate is obtained by ionization of bicarbonate out of one H+, and bicarbonate is obtained by ionization of carbonic acid H+. Bicarbonate and carbonic acid are called weak acids due to incomplete ionization, so correspondingly, their ionization products carbonate and bicarbonate have a strong tendency to attract an H+. This H+ is usually stripped from the water, leaving behind the corresponding OH-, making the solution alkaline.

Generally, the positive ions of a salt correspond to a strong base (such as Na+ corresponding to Naoh), while the negative ions correspond to weak acids (such as carbonate corresponding to bicarbonate, bicarbonate corresponding to carbonic acid), so that the composition of the salt is called strong alkali weak salt, which is alkaline. On the contrary, such as NH4SO4, it is called a weak base and strong salt, which is acidic. The acidity and alkalinity of salt is measured by its anionic and cationic properties.

Answer: The reason why the aqueous solution of NaHCO3 is alkaline is due to the hydrolysis of HCO3- ions. First, NaHCO3 is ionized in water (NaHCO3 = Na+

HCO3-), secondly, the hydrolysis reaction occurs when the bicarbonate ions combine with the hydrogen ions ionized by water, (HCO3-

h2o=h2co3

oh-), the middle = is a reversible symbol], this process makes an extra part of the hydroxide ions in the solution, so that the concentration of hydroxide ions in the water is greater than the concentration of hydrogen ions, so the solution is alkaline.

Because it is an aqueous solution of strong alkali and weak salt, the hydrolysis ability of Na ions is greater than the ionization ability of bicarbonate, that is, the concentration of hydroxide ions is greater than that of hydrogen ions, so its aqueous solution is alkaline .........

Na2SO4 is basic.

Na2SO4 refers to sodium sulfate, which is colorless, transparent, large crystals or small granular crystals. Its solution is mostly neutral, soluble in glycerol but not in ethanol. Inorganic compounds, high-purity, fine-grained anhydrous are called Yuanming powder.

Yuan Ming powder, white, odorless, bitter crystals or powders, hygroscopic. The shape is colorless, transparent, large crystals or granular small crystals. Sodium sulfate is easy to absorb water when exposed to air, and produces sodium sulfate decahydrate, also known as miscanthus nitrate, which is alkaline.

Main uses of sodium sulfate:

1. It is used in the chemical industry to manufacture sodium sulfide, sodium silicate, sodium silicate water glass and other chemical products.

2. The cooking agent used in the paper industry to make sulfate pulp.

3. The glass industry uses soda ash instead of soda as a co-solvent.

4. The textile industry is used to prepare vinylon spinning coagulant.

5. Used in non-ferrous metal metallurgy, leather, etc.

6. Used as analytical reagents, such as dehydrating agents, digestion catalysts for nitrogen determination, and interference inhibitors in atomic absorption spectroscopy analysis. It is also used in the pharmaceutical industry.

7. It is used in chemical industry, papermaking and glass, dyes, printing and dyeing and pharmaceutical industries, and is also used in the manufacture of synthetic fibers, tanning, non-ferrous metallurgy, porcelain enamel, etc., and is also used as an additive in detergent and soap.

The above content refers to Encyclopedia—na2SO4

NaHCO3 is hydrolyzed and ionized in the solution, the degree of hydrolysis is greater than the degree of ionization, the solution is alkaline, and the hydrolysis equation is: HCO3-+H2O?H2CO3+OH-,NaHCO3 solution is alkaline, and the degree of hydrolysis is greater than the degree of ionization, C(OH-) C(H+), so the ion concentration relationship is:

C(Na+) C(HCO3-) C(OH-) Good C(H+) C(CO32-);

So the answer is: C(Na+) C(HCO3-) C(OH-) C(H+) C(CO32-).

Sodium bicarbonate (Nahco), commonly known as baking soda. White fine crystals, less soluble in water than sodium carbonate. It is an industrial chemical with low toxicity.

Solids above 50 begin to gradually decompose to produce sodium carbonate, carbon dioxide and water, and completely decompose at 440. Sodium bicarbonate is an acid salt formed after neutralization of strong alkali and weak acid, which is weakly alkaline when dissolved in water. This property allows it to be used as a leavening agent in the food production process.

Sodium bicarbonate will remain sodium carbonate after being used as a friend of the liquid, and the use of too much shirt will make the finished product have an alkaline smell.