Why don t HCO3 coexist in acidic solutions?

The so-called ion coexistence is essentially a question of whether there is a reaction between ions. If the reaction occurs in solution, it cannot coexist. To see whether the reaction can occur, it is not only because of the precipitation, gas, water, and substances that are difficult to ionize, but also because the solution is acidic and alkaline, colored, colorless, and whether the redox reaction can be carried out.

H cannot coexist with CO32, HCO3, S2, HS, HSO3, SO32, etc.

In a strongly acidic solution, there can be a large number of weak acid ions: such as CO32, HCO3, S2, HS, SO32, SiO32-, AlO2, F, etc., nor can there be a large amount of OH.

Because HCO3- is a weak acid ion, neither weak acid nor weak base can coexist with alkaline and acidic.

The acidic solution contains a large amount of hydrogen ions H+, and bicarbonate will combine with the hydrogen ions in it to form water and carbon dioxide, i.e.:

HCO3)- H+ = H2O + CO2 (gas symbol).

Bicarbonate combines with hydrogen ions in acidic solutions to form water and carbon dioxide gas, so it cannot coexist.

Helpless...

Because bicarbonate readily reacts with H+ in acidic solutions to form water and carbon dioxide.

Bicarbonate combines with hydrogen ions in an acidic solution to produce water and carbon dioxide.

hco3- +h+=h2o +co2

Oh, this is an exception though in chemistry HCO3-

Hydrolysis and ionization are a pair of reverse reactions, the stronger the hydrolysis reaction, the weaker the ionization reaction will become, and vice versa.

CO32- is the dominant hydrolysis reaction in water C032- +H20 = HC03- +OH-

HC03- is also mainly hydrolyzed in water (because NaHCO3 is alkaline in aqueous solution, it is recommended to turn to the high school book on the second floor), but the degree of CO32- hydrolysis is stronger than HCO3-, that is to say, there is more OH- in Na2CO3 solution, so the pH of Na2CO3 solution is greater than NaHCO3

Again, HCO3=H+ +CO3- is a rather weak reaction and is not the main reason why the pH of the Na2CO3 solution is greater than that of NaHCO3.

HCO3- can be ionized and hydrolyzed in aqueous solution, ionization makes the solution acidic, while hydrolysis makes the aqueous solution alkaline, but the hydrolysis of HCO3- dominates, making HCO3- alkaline in water. Bicarbonate is a conjugate base of carbonic acid and a conjugate acid of carbonate ions.

Both carbonate and bicarbonate are ions, and they are weak acid ions, both of which are easy to exist in alkaline conditions, carbonate is less acidic than bicarbonate, so it is easier to hydrolyze, so the alkalinity of the aqueous carbonate solution is stronger than that of the aqueous solution of bicarbonate. The degree of hydrolysis of carbonate ions is large, and most of the salts bound to bicarbonate are soluble salts, while many salts bound to carbonate ions are insoluble, and bicarbonate can be combined with hydroxides to form carbonate and water. Bicarbonate and carbonic acid do not react, if the reaction bicarbonate loses an h and becomes carbonic acid, the carbonic acid gets an h and becomes bicarbonate, which is the same as no reaction.

Bicarbonate reacts with acetic acid and phosphoric acid, and phosphoric acid is a moderately strong acid.

Mainly because of the accompaniment effect after hydrolysis in water.

CO32 - +H+=HCO3- (partial) +H+=H2CO3 (partial part).

HCO3-+H+=H2CO3 (HCO3- is more hydrolyzed and is present as H2CO3).

It can also be seen as a reaction of strong acid to weak acid.

na2co3+h2co3=2nahco3

The reduction of SO32- is strong, the acidity is considered to be a strong acid, and the ionization is greater than the hydrolysis, so the tragilohydrosulfite in the band is slightly more acidic.

hso3=h+ +so32-

Calculate to use the PKA of the equilibrium solution to acid, that does not Lu Pei stared at the course of knowing that lz has not been learned, and the teacher will talk about it after the second year of high school.

HCO3-ofProtonic acidIt is carbonic acid.

HCO3 is an ion, an acid called carbonic acid, which reacts with H+ to form H2CO3, but this acid is unstable and easy to decompose into H2O and CO2, and CO2 has acid-holding properties.

The acid-base ion theory was developed by Arrhenius based on his theory of ionization. He believed that hydrogen ions could be ionized in water.

and no other cations are produced.

The substance is called acid. Hydroxide ions can be ionized in water and no other anions are produced.

The substance is called a base. The essence of the acid-base neutralization reaction is the combination of hydrogen ions and hydroxide ions to form water.

Limitations. Since its description of acids and bases is limited to aqueous solutions, there are some limitations. For example, ammonium chloride.

The aqueous solution is acidic, but it does not contain hydrogen ions per se; For example, the aqueous solution of ammonia is alkaline, and it was erroneously believed that NH3 and H2O form weak electrolytes.

NH4OH molecule, which is then dissociated to OH-etc.

Since Arrhenius's theory of acid-base ions could not solve the problems of acid-base reactions in non-aqueous solutions, br nsted and Lowry proposed the acid-base proton theory in 1923.

The above content refers to: Encyclopedia - acid-base proton theory.

The strong acid solution contains a large amount of H+, H+ and HCO3- reaction, and H+ and the solution of NO3- after mixing, there is strong oxidation, can oxidize Fe2+ to Fe3+, so can not coexist in large quantities.

Because the hydrolyzed ion equation for Na2CO3 is CO32-H2O=HCO3-

In the same way, the acid corresponding to NaHCO3 is H2CO3

In the case that the concentration of the solution is not too small, this statement is correct!

The relationship between C(Na+)>C(CO32-)>C(OH-) is not difficult to understand, right? The sodium ion in sodium carbonate is twice that of the carbonate ion, and about one-tenth of the carbonate ion is hydrolyzed to produce hydroxide ions and bicarbonate ions, so hydroxide ions and bicarbonate ions are about.

It is about one-ninth of carbonate ions;

The three relationships of C(OH-)>C(HCO3-)>C(H+) are as follows: the concentrations of hydroxide ions and bicarbonate ions should be equal from the perspective of hydrolysis of carbonate ions, but there is still further hydrolysis of bicarbonate ions, hydroxide ions increase, and the concentration of bicarbonate ions decreases; Hydrogen ions are calculated according to the ionic product constant of water, and the concentration is the smallest!

If the concentration of the solution is too low, the concentration of hydrogen ions may be greater than that of bicarbonate ions.

<>pH=7, the standard is neutral, and the reaction in the diagram is in dynamic equilibrium, so carbonate and bicarbonate are in dynamic equilibrium and coexist.