A few questions about the hydrolysis of high and high salt are troublesome to the masters.

1 pair: Because some salts are completely ionized, they are not hydrolyzed in water.

2 Hydrolysis equation HCO3- +H2O = H2CO3 + OH- produces OH- makes the solution alkaline.

The ionization equation HCO3-=H+ +CO32- produces H+ which makes the solution acidic.

And because the solution of NaHCO3 is alkaline, the degree of hydrolysis is greater than that of ionization.

To solve this kind of problem, you first have to judge the acidity and alkalinity of the solution, and then you can judge it, and of course you can also use their equilibrium constant, but you don't need to do the problem in high school.

3 Some of them are related, and I don't know very well, but I rarely encountered ionization and hydrolysis in high school.

Hehe, I hope mine is helpful to you This chapter should do some questions to make yourself feel and give you a look.

1 Let's talk about the third first, the hydrolysis of salts, in fact, is the reverse reaction of ionization of weak electrolytes, for example, for sodium acetate NaAC, its hydrolysis AC-+H2O=HAC+OH- is the reverse reaction of HAC=H++AC-, in professional terms, it is PKA+PKB=14, so the stronger the acidity of an acid (the greater the KA), the smaller the degree of hydrolysis of its acid roots (KB).

2 Second, the ionization of NaHCO3 is HCO3-=H++CO32- out of hydrogen ions, hydrolysis into HCO3-+H2O=H2CO3+OH- out of hydroxide, because the aqueous solution of NaHCO3 is alkaline, indicating that there are more hydroxide groups out, that is, the degree of hydrolysis is large.

3 First, first of all, for an acid, the stronger its acidity, the less hydrolyzed its acid roots, HCL is a strong acid, almost not hydrolyzed. The same is true for alkalis, the more alkaline they are, the less they are cationic hydrolyzed.

With the exception of some special, covalent salts (e.g., lead acetate, Pb(Ac)2), salts dissociate as soon as they are dissolved in water.

1. First of all, "there is weak hydrolysis" refers to the salt weak acid acid, and the weak alkali cation is hydrolyzed. If the salt contains a salt weak acid, one of the weak base cations is monohydrolysis, and if the salt also contains salt weak acid, the weak base cation is double hydrolyzed. The sodium ion in NaCl is a strong alkali cation, and the chloride ion is a strong acid acid ion, so sodium chloride is not hydrolyzed.

2. First of all, NaHCO3 ionization: NaHCO3=NA+ +HCO3-; Ionized HCO3- continues to ionize HCO3- =H+ +CO3 2- (not completely ionized partial ionization, reversible sign cannot be typed) It is also hydrolyzed when HCO3- is ionized: HCO3- +H2O = H2CO3 + OH- (not an equal sign, it is a reversible symbol, it cannot be typed) Finally ionized CO3- hydrolysis:

The first step is to hydrolyze CO3- +H2O = HCO3- +OH-, and the second step is to hydrolyze HCO3- +H2O = H2CO3 + OH- (not an equal sign, it is a reversible symbol, which cannot be typed). However, the hydrolysis of NaHCO3 is greater than ionization because its solution is alkaline.

3. There is a relationship. If the electrolyte contains a weak acid or a weak alkali cation, the more likely it is to hydrolyze, the more equilibrium it will move to the direction of hydrolysis, and if it is a weak acid and weak alkali salt, then it is double hydrolysis, and it is completely and completely hydrolyzed. That is, if the weak acid is more acidic, its ionization is weaker, but the corresponding salt hydrolysis is stronger (the weaker the alkalinity of the weak base, the weaker the ionization, but the stronger the hydrolysis of the corresponding salt).

The weaker the electrolyte properties, the weaker the ionization, but the stronger the corresponding salt hydrolysis.

What is the problem, as long as you follow the hydrolysis of weak root ions, and then pay attention to their hydrolysis equation, and then there is the problem of equilibrium movement, as long as you understand that the principle of chemical reaction is the change of ion concentration, there is no problem to learn this part. Come on.

Because NaCl is a strong acid, a strong alkaline salt 2, because NaHCO3 is alkaline, the degree of hydrolysis is large3 no.

Ammonium acetate is a strong electrolyte, and in general, salts are found in all but a few such as:

Lead acetate is a weak electrolyte, and the rest are strong electrolytes. 】

Most of the compounds composed of weak acids and weak alkalis are strong electrolytes, and a few are not, as above. 】

All salts are strong electrolytes, [still the same answer, very few salts are not strong electrolytes.] Chlorine is not an electrolyte and is not a non-electrolyte.

Both electrolytes and non-electrolytes are chemical compounds.

The pH decreases when pure water is heated, (because.

The concentration of hydrogen ions increases), it is still neutral, as long as it is pure water, any temperature is neutral.

The evaporation of the solution is lower than the burning temperature, and some substances decompose at high temperatures.

Barium bicarbonate solution is evaporated to obtain barium carbonate, and barium oxide is obtained by burning at high temperature) to list several groups of ions that often undergo double hydrolysis reactions, such as AL

co32-hco3-

alo2-/

sio32-/

s2-/hs-/clo-

fe3+--

co32-hco3-

alo2-/

sio32-

clo-nh4+

alo2-/

sio32-

In middle school chemistry, as long as you remember the above three groups of thorough double hydrolysis, it is enough, I wish you progress in chemistry!

1 (08 Chongqing volume) to three parts, L CH3Coona solution added a small amount of NH4NO3, Na2SO3, FeCl2 to the body (ignoring the change of solution volume), then the change of CH3CoO- concentration is (A) A decreased, increased, decreased.

2 (08 Hainan volume) Among the following ion equations, the hydrolysis reaction is (c).

a．hcooh+h2o hcoo－ +h3o+b．co2+h2o hco3－ +h+ c．co32－ +h2o hco3－ +oh－d．hs－ +h2o s2－ +h3o+

4.The following processes or phenomena that are not related to salt hydrolysis are: (b) a soda ash solution degreasing bIron rusts in a humid environment c heats the ferric chloride solution and becomes darker in color dThe concentrated sodium sulfide solution has a foul smell.

5.When the amount and concentration of the substance are the same, among the following solutions that can react with both NaOH solution and hydrochloric acid solution, the largest pH is (b) solution.

6.(07 National Volume II) The pH of mol L NaHCO3 solution is closest to (C).

7.(04 national volume) at room temperature, the following 4 solutions have the smallest pH (A).

A ·l 1 acetic acid solution, B mol·l 1 acetic acid and mol·l 1 NaOH solution, C mol·l 1 acetic acid and mol·l 1NaOH solution, D pH 2 hydrochloric acid and pH 12 NaOH solution.

8.(08 national volume) acetic acid (HA) is known to be weaker acidic than formic acid (HB), in the amount and concentration of the substance is NAA and NAB mixed solution, the following order is correct (a) a c (OH) > C (HA) > C (HB) > C (H+) B C (OH-) > C (A-) > C (B-) > C (H+) C C (OH-)> C (B-)> C (A-)> C (H+) D C (OH-)> C (HB)> C (HA)> C (H+)

If you need a process, you can ask about it.

After heating, BC will react with oxygen to form metal oxides, and D will decompose.

The hydrolysis equation FeCl3+3H2O=Fe(OH)3+3HCl, due to the volatilization of HCl, the hydrolysis equilibrium shifts to the right to obtain Fe(OH)3, and Fe2O3 will be obtained if the burning continues. To obtain FeCl3, it must be heated and evaporated under the gas flow of HCl, because HCl can inhibit the right shift of hydrolysis.

The same is true for al(NO3)3 in c.

Calcium bicarbonate is heated and decomposed to obtain calcium carbonate. If the heating temperature exceeds 898 degrees, calcium oxide will be obtained.

Therefore, the answer to this question is A

Hydrolysis is the chemical reaction between salt and water, which is a reversible reaction, contrary to the neutralization reaction, only weak acid acids and weak base cations will be hydrolyzed, sodium carbonate is pH greater than sodium bicarbonate solution, because the degree of hydrolysis of CO32- is greater than that of HCO3-, CO32- is hydrolyzed in two steps, CO32-+H2O===HCO3-+OH-, HCO3-+H2O===H2CO3+OH-, mainly in the first step, and HCO3- is only hydrolyzed in the latter step.

1. The pH value (NH4)2SO4 is larger, because NaHSO4 is more acidic than (NH4)2SO4;

2,The hydrolysate of [Al(OH)4]- is Al(OH)3 precipitate;

3. Because some acids and bases are volatile, when the pH value of the solution changes, and this change should be irreversible due to the volatilization of some substances, the salt will be hydrolyzed; NaCO3 solution and Na2SiO3 solution are alkaline and will react with the glass and corrode the glass stopper, so a rubber stopper should be used; NH4F solution stored in plastic bottles is related to hydrolysis, because F ions will react with glass and promote hydrolysis;

4. Magnesium oxide is an alkaline oxide, which reacts with acid to produce magnesium chloride, and iron ions will be hydrolyzed to produce iron hydroxide precipitation in the case of pH = 3, and the precipitation of ph = is complete, and magnesium ions need higher alkalinity to generate magnesium hydroxide precipitation. In terms of practical effect, it is best to use magnesium oxide, after all, magnesium carbonate will dissolve part of the carbon dioxide in water, otherwise we will not be able to drink carbonated drinks!

1.I remember that it was sodium bisulfate large, and the reason was back data.

2.This one cannot be hydrolyzed, only ionized.

3.Generally, it can produce any volatile acids, easy to precipitate acids, and they are unstable anyway. Sodium carbonate and sodium silicate yes, the last one I don't know.

4.Iron pH is equal to 3 to start precipitation, 5 precipitation is complete, magnesium ion pH 9 when the precipitation is complete. B and C both introduce impurities, and D, carbonate is saturated, so the carbon dioxide also goes out when the iron ions are presidised.

1 I don't know. See data. 2 Same as above Not hydrolyzed.

Na2SiO3 hydrolyzes alkaline, and alkaline substances can be stored without a glass stopper, which will stick. F-ions are hydrolyzed to form HF, which reacts with the glass bottle. 4. In order to adjust the pH Fe3+, magnesium oxide will precipitate at 3-5pH, and magnesium carbonate is the same.

Hello! Your question is very good!

1) CH3COOK HCl CH3COOH+KCl The reaction is a typical process of making weak acids from strong acids, which is irreversible, so the reaction is complete.

2) The ion equation of the hydrolysis reaction of acetate ch3coo + h20 = (reversible) ch3cooh + 0h cannot be simply understood as the reaction of acetate with hydrogen ions, there is a problem with the ion equation you wrote!

Hope it helps!

Lead acetate is a strong alkaline weak salt, which will be hydrolyzed into alkaline in aqueous solution.

The hydrochloric acid solution is a strong acid, which will react with the hydroxide hydrolyzed by potassium acetate in one step, but it is mainly the principle of strong acid to weak acid, and the hydrochloric acid solution produces weak acid in a salt that is weaker than it.

After the weak acid is prepared, CH3COOH===CH3COO- +H+, so the reaction of potassium acetate and hydrochloric acid is a complete reaction.

In this way, sometimes it is regarded as a complete reaction, but in fact it is not a complete reaction, depending on the specific question, if it is a chemical balance, the problem of weak electrolytes must be considered......And this kind of question must not be considered, otherwise it will definitely not be able to calculate the answer, because the questions are already wrong, and it is impossible to fully respond to it......

First of all, this is a dynamic complete reaction, specifically for this reaction CH3COO+H=(reversible) CH3COOH exists, but cannot be reflected. Because it is under acidic conditions, the excessive equilibrium of H ions moves towards CH3COOH. So there is a directed reaction, and a complete reaction.

In addition: the ionic equation of the hydrolysis reaction of acetate ch3coo + h20 = (reversible) ch3cooh + 0h

ch3cooh=(reversible) ch3coo+h (this is ionization) I don't know what the one you wrote?

The first question, select, add water to dilute the concentration to decrease. c,。d, the solution is alkaline after adding sodium hydroxide.

The second question, d, has a solubility product of 4x10 -10 and can be precipitated.

The third question, b, the amount concentration and volume of the substance are the same, that is, the amount of the same substance, then it should be pH=, easy to ionize and difficult to hydrolyze, so the pH of Naf is smaller. d, when it is 8, ha is weak acid, which cannot be calculated by multiples. So choose A.

Question 4 C, Ammonia excess, C(NH+)>C(Cl-). a, sodium hydroxide should be excessive. Pick B.