Why is it said that the hydrolysis of carbonate ions is stronger than that of bicarbonate ions

Yes, explanation 1: the hydrolysis constant of carbonate is 10, and the hydrolysis constant of bicarbonate is 10.

Therefore, carbonate is more susceptible to hydrolysis.

Another way to explain it: the first step of carbonic acid is easier to ionize, and bicarbonate is generated; The second step ionization produces carbonate weaker than the first step. Easy ionization is not easy to hydrolyze, so the hydrolysis ability of carbonate is relatively strong.

Because carbonic acid is a weak acid and is not easy to ionize, carbonate ions are easily combined with hydrogen ions ionized by water to form bicarbonate ions, and the solution is weakly alkaline after combination, and bicarbonate ions are not easy to combine with hydrogen ions under alkaline conditions, that is to say, the first step of carbonate has a large degree of hydrolysis, and the second step of hydrolysis has a small degree of hydrolysis.

According to the ionization of multiple weak acids, it is step-by-step, only one hydrogen ion can be ionized in one step, and the more difficult it is to ionize behind the slag circle, the less hydrogen ions are ionized. So the ionization steps of H2CO3 are:

h2co3h^＋hco3^

hco3^h^＋co3^

The combination with hydrogen ions is the opposite of the ionization of weak acids, and the second step of ionization above the self-isolation defeat is easier to combine with hydrogen ions than the first step, and it binds more, that is, carbonate ions are easier to combine with hydrogen ions than bicarbonate ions.

Hydrolysis is the reverse process of ionization of an acid or base, i.e., hydrolysis into the corresponding acid or base. Both carbonate ions and bicarbonate ions are acid groups that are hydrolyzed to form weak acids that are to be combined with hydrogen ions, and carbonate ions are easier to combine with hydrogen ions than bicarbonate ions, so carbonate ions are more easily hydrolyzed than bicarbonate ions.

So it is easier to combine with hydrogen ions, as well as hydrolysis, both carbonate ions.

OK. Small amount of hydrogen ions: Co H = HCO Sufficient amount of hydrogen ions:

CO 2H = H O+CO Although it contains carbon, the substances containing carbonic acid refer to the roots of denier are mostly inorganic. Carbonate is a weak acid that is easily hydrolyzed in water to produce bicarbonate ions and hydroxide ions, thus biasing the water towards alkaline.

There are many carbonates, and there are many common carbonates in life, such as soda ash (sodium carbonate), limestone (the main ingredient is calcium carbonate), etc. With the exception of potassium carbonate, sodium carbonate, and ammonium carbonate, carbonate is generally insoluble in water. With the exception of carbonates of alkali metals, most of the remaining carbonates are susceptible to thermal decomposition.

There is no necessary connection between the two.

Carbon disturbance landrate has a strong ability to bind hydrogen ions, indicating that carbonic acid is easy to ionize hydrogen ions without delay, which means that carbonic acid is a weak acid.

Carbonic acid is easy to decompose because carbonic acid is unstable. To put it a little higher, it is because of the presence of carbonic acid with the same carbon bihydroxyl structure. The homocarbon bihydroxyl structure is easily dehydrated to produce a stable carbonyl group. Structure.

Carbonate is an anion with the chemical formula CO32-. When carbonate receives a hydrogen ion, it can form an acid molecule - cavity carbonated acid with the chemical formula H2CO3. Carbonated acid is a weak acid that releases small amounts of hydrogen ions, making the environment acidic.

This process is known as dissociation of carbonic acid and can also be written as the following reaction:

h2co3 ⇌ h+ +hco3-

In this reaction, H+ stands for hydrogen ion and HCO3- stands for a traveling anion called hydrocarbonate, which is the conjugate base of carbonated acid. Therefore, carbonate is able to give hydrogen ions because it can combine with hydrogen ions to form carbonic acids, which in turn can release small amounts of hydrogen ions.

The hydrogen ions react with the bicarbonate ions, and the ionic equation for the reaction is panicle loss:

Bicarbonate reacts with hydrogen ions, and the products are water and carbon dioxide.

When there are few macro-talk hydrogen ions, the carbonate reacts with the hydrogen ions to form bicarbonate; Whereas, when a large number of hydrogen ions are present, the carbonate reacts with the hydrogen ions to form carbon dioxide and water.

The equation for the chemical reaction of carbonate and hydrogen ions is:

1. Cun Qingla in a large number of hydrogen ions: 2H+ +CO3 2- =H2O+CO2; Cover the difference.

2. When there is a small amount of hydrogen ions: H+ +CO3 2- = HCO3-.

This can only be explained by the results of previous studies.

The primary hydrolysis constant of carbonate kb1=, the secondary hydrolysis constant kb2=, the primary hydrolysis constant is much greater than the secondary hydrolysis constant, so the degree of hydrolysis of carbonate is greater than that of bicarbonate.

Or to explain it this way, when the carbonate undergoes primary hydrolysis, the hydrogen ions in the solution become smaller, and the secondary hydrolysis becomes difficult.

In fact, the carbonate in carbonate will undergo a hydrolysis reaction, and there are two stages of hydrolysis. The first stage is the reversible formation of bicarbonate and hydroxide by carbonate and water, which is very weak, and the second stage of hydrolysis is the reversibility of bicarbonate and water to form carbonic acid and hydroxide, which is weaker than the first stage. Therefore, there are very small amounts of carbonic acid molecules in carbonate solution.