Why phenol and CO2 react only to produce NaHCO3, why Na2 can t be understood

First of all, you treat CO32- as an acid, so you think that weak acids are made from strong acids, and strong acids HCO3- become weak acids CO32-. This is a mistake. The definition of the so-called acid base is:

In the reaction, it is the acid that does not provide protons, and it is the base that accepts protons. So when a protonic acid provides a proton, it becomes its conjugate base.

For example: HCO3- CO32- +H+ HCO3- loses a proton in this reaction, so it is an acid, and you see CO32- is actually a product of HCO3- after losing protons, CO32- itself no longer has the ability to lose protons, it can only bind protons, so we think CO32- is a base. And your mistake is to mistake CO32- for acid.

In fact, we call HCO3- and CO32- in reactions like HCO3- CO32- +H+ conjugated acid-base pairs. That is, the acid becomes alkaline after the reaction, and the alkali becomes acidic after the reaction.

Let's talk about phenol again.

Sodium phenol + H2CO3 Phenol + NaHCO3 By strong acid in the reaction we mean H2CO3 and weak acid refers to phenol, not NaHCO3! As mentioned earlier, NaHCO3 is a conjugate base of H2CO3 in this reaction.

If sodium phenol reacts with NaHCO3, it must be this reaction:

Sodium phenol + NaHCO3 Phenol + Na2CO3

The two acids in the reaction are NaHCO3, phenol; The two bases are sodium phenol, Na2CO3, in fact, phenol is more acidic than NaHCO3, so the reaction cannot occur.

Because phenol is less acidic than carbonic acid, and there is a principle of forced weakness, it can only be generated.

Do not react. co2 + na2co3 + h2o= 2nahco32）co2 + h2o = h2co3

As a result of the reaction in 1)2) above, CO2 is dissolved in saturated Na2CO3 solution and also in unsaturated Na2CO3 solution.

CO2 is insoluble in saturated NaHCO3 solution because theoretically there is no Na2CO3 in the saturated NaHCO3 solution and the above reaction cannot be carried out, while CO2 does not react with Na2CO3.

The saturated NaHCO3 solution contains an excess of (-HCO3 ions, which prevents CO2 from reacting with H2O. (i.e., CO2 + H2O = H2CO3 reaction does not occur) so it is insoluble in saturated NaHCO3 solution, which shows that saturation and unsaturation have an effect.

C6H5OH + Na2CO3 = NaHCO3 + C6H5OH sodium phenol is sodium to replace the H in the hydroxyl group, carbon dioxide is first dissolved in water to form carbonic acid, carbonic acid hydrolysis to form H ions and bicarbonate ions, the formation of H ions will replace the sodium ions in sodium phenol to form phenol reduction, then there will be a large number of sodium ions and leakage early Zen bicarbonate ions in the solution, and the carbonic acid back dust ion is there, but rarely, it is formed by the second ionization of bicarbonate.

It's not very clear whether it's a replacement.

But it won't be tested like this, its test center is.

Strong acids make weak acids.

The acidity from large to small is: carbonic acid, phenol, sodium bicarbonate.

Carbon dioxide plus water is carbonic acid.

Then the acidity of sodium carbonate is carbonic acid.

The condition for the metathesis reaction to occur is that the product has a precipitate or gas, carbon dioxide in water is carbonic acid, and it reacts with sodium bicarbonate to produce neither precipitate nor gas, so it does not react.

According to the acidity: HC>H2CO3 (CO2+H2O)>HCO3->CO32-

So CO32- +CO2 + H2O ===2HCO3- is forced weak.

HCO3- +CO2 + H2O === does not react HCO3- +H+ *****H2O +CO2 by forcing weak.

When you encounter this doubt, you can use the hypothetical method:

If reacted: HCO3- +CO2 + H2O ===H2CO3+HCO3-

or 2HCO3- +CO2 + H2O ===2H2CO3+CO32-

Since CO2 + H2O is H2CO3, you can see that the reactants in turn form reactants, which is not possible.

When a saturated NaHCO3 solution is added to a phenol solid, the following reaction occurs:

2c6h5oh + na2co3 → 2nac6h5o2 + co2 + h2o

Among them, NaHCO3 dissolves into Na2CO3 and releases carbon dioxide and water. Carbon dioxide gas forms bubbles and escapes, while phenol reacts with Na2CO3 to form sodium phenol salts and water. This results in a lightening of the color in the phenol solid, as the solubility of phenol increases with temperature, and heating helps to facilitate the reaction.

In addition, the reaction also causes a change in the pH of the solution, from acidic to basic.

It is important to note that this reaction may generate some heat, so care needs to be taken to avoid spilling the solution or causing other safety concerns.

1) Phenol is slightly soluble in water, and it will also dissolve in saturated NaHCO3 solution, and most of them are in a semi-solid state!

2) Phenol is very acidic and cannot be reversed with NaHCO3 solution!

No matter how much CO2 passes, only phenol and sodium bicarbonate will be produced. The chemical equation is C6H5ONA+CO2+H2O==C6H5OH+NaHCO3, and the ion equation is C6H5O-

co2h2o

c6h5oh

hco3-。There are two reasons for this:1

Carbon dioxide and water are easy to combine to form carbonic acid, and carbonic acid is stronger than phenol, according to the principle of strong acid and weak acid reaction to form weak acid and strong acid (that is, "strong acid to weak acid"), so phenol is formed. 2

Why is only bicarbonate generated? This is related to ionization equilibrium. The ionization of carbonic acid is divided into two steps: H2CO3<==>H++HCO3-, HCO3-<==>H++CO3

2-。However, the ionization constant of the second step is much smaller than that of the first step, so the second step can be regarded as basically non-occurring. Or that phenol is not acidic enough to break the ionization equilibrium of the second step, so the hydrogen in the bicarbonate will not be "snatched away".

In summary, the only products produced are phenol and sodium bicarbonate.

What is generated is sodium bicarbonate, and the acidic boundary of phenol is the same as that of carbonic acid and sodium bicarbonate, and the results can be obtained by the law of strong acid to weak acid.

Phenol is weaker acidic than carbonic acid, (i.e., the degree of phenoxy hydrolysis is between carbonate and bicarbonate), according to the principle of strong acid to weak acid, even if carbonate is generated, it will become phenol again. So only bicarbonate is generated, i.e. sodium bicarbonate.

Carbonic acid is more acidic than phenol, and phenol is more acidic than bicarbonate.

The solid name is commonly known as carboxic acid.

Therefore, sodium phenol reacts with CO2 and H2O to form sodium bicarbonate, but not sodium carbonate, which is to comply with the theorem that strong acid makes weak acid.

1. Carbon dioxide is introduced into the sodium phenol solution, and the reactants generate phenol and sodium bicarbonate. Because the acidity of H2CO3, HCO3-, and phenol is H2CO3

Phenol HCO3-, which can be prepared according to soluble strong acids, can make weak acids, while weak acids cannot make soluble strong acids in solution. Therefore, "when carbon dioxide is introduced into a solution of sodium phenol, the reactants can only produce phenol and sodium bicarbonate, but not sodium carbonate." ”

2. Sodium phenol, sodium phenoxy, national standard number: 83013CAS.

Phenol is weakly acidic and reacts with NaOH at room temperature to produce sodium phenol. It is mainly used as a preservative, an intermediate in organic synthesis, and is used in gas masks to absorb phosgene.

A small amount of carbon dioxide is introduced into the solution of C6H5O-+CO2+H2O=C6H5OH+HCO3-phenol sodium solution: CO2+H2O+C6H5ONA, C6H5OH

nahco3

Acetaldehyde undergoes a catalytic oxidation reaction to generate acetic acid, which is heated by 2CH3CHO+O2 catalyst.

2CH3COOH, which belongs to the oxidation reaction,

No matter how much CO2 is passed, only phenol and sodium bicarbonate will be generated, and it is even more outrageous to say that salicylic acid is generated. Chemical equation: C6H5ONA+CO2+H2O==C6H5OH+NaHCO3, ion equation:

c6h5o- +co2 + h2o ==c6h5oh + hco3-.There are two reasons: 1 Carbon dioxide and water are easy to combine to form carbonic acid, and the acidity of carbon dioxide is stronger than that of phenol, according to the principle of reaction between strong acid and weak acid to form weak acid and strong acid (that is, "strong acid to weak acid"), so phenol is generated.

2 Why is only bicarbonate generated? This is related to ionization equilibrium. The ionization of carbonic acid is done in two steps:

h2co3h++hco3-,hco3-h++co3 2-.However, the ionization constant of the second step is much smaller than that of the first step, and the second step can be regarded as basically non-occurring. Or that phenol is not acidic enough to break the ionization equilibrium of the second rough step, so the hydrogen in the bicarbonate will not be "snatched away".

In summary, the only products produced are phenol and sodium bicarbonate.

From the perspective of carbonic acid penetrating sodium phenol but making the solution turbid to form phenol (carbonic acid can make phenol), it shows that carbonic acid is stronger than phenol.

However, the acidity of phenol is stronger than that of H bicarbonate, and according to the principle of strong acid old orange powder to produce weak acid, sodium phenol can only be generated by reacting with carbon dioxide.

Sodium phenol can react with sodium carbonate, and the acidic non-carbonated nature of bicarbonate is weak, and it is precisely because of Shi's weakness that sodium bicarbonate will be generated.

Phenol is acidic but weaker acidic than carbonic acid but stronger than bicarbonate.

i.e. acidic: HCO3-<

Ho-n-phenol nuclear lease H2CO3

So when CO2 passes into sodium phenol.

Since there is a code for strong acids to produce weak acids, CO2 and water should be used to form carbonic acid (H2CO3).

But due to the forced weakness of Mr. became Na2CO3 and phenol but because of the CO32- acidic ratio.

Phenol is strong so it continues to react with the sound into a weaker acid HCO3-note CO3

Both 2- and HCO3- are hydrolyzed and are alkaline, acidic is the original acid CO32 that corresponds to this root, and H2CO3 corresponds to it

HCO3- corresponds to itself, because HCO3- can be reionized with hydrogen ions).