Chemistry How to learn the hydrolysis of salts and what is the hydrolysis of salts?

Hydrolysis of salts. To put it bluntly.

It is the ion of salt in the solution that reacts with water to decompose water H2O.

h+ or oh-

Like what. nahco

3 of them. hco

3- can combine with one of the H of the water molecule H2O, so that the water molecule decomposes into an OH- solution that is alkaline.

The strength of the alkalinity of the solution depends on what substance it is, and it also depends on the solubility (generally compared with alkalinity under the same conditions).

For example, for acids, the stronger the acidity of the acid, the weaker the alkalinity of the solution corresponding to its salt ions, such as HCl strong acid and HClO weak acid, the ions are respectively.

cl - and. clo-

NaCl solution is neutral (not alkaline), while NaClo is alkaline.

In the same way, for alkalis, the stronger the alkalinity of the base, the weaker the acidity of the solution corresponding to its salt ions.

Like what. ba(oh)2, and al(oh)3

BACL2 is neutral.

Alcl3 is acidic.

All of the above are required in the accumulation of large amounts of acidic strength in relation to acids.

on the basis of the alkalinity of its salt.

In the same way, it is also necessary to know the alkalinity of alkalis.

The size of the pH value, the greater the acidity, the smaller the pH value, the stronger the alkalinity, and the greater the alkaline pH.

Some substances are directly ionized with H+ or OH-, and they are generally not hydrolyzed. For example, NaHSO4 is acidic.

And. NAOH is alkaline.

Wait. Some salts correspond to strong acids (whose ions are completely ionized and do not interact with water molecules), so the salt solution is neutral. For example, NA

SO4, corresponding to H2SO4 strong acid.

The hydrolysis of salt is mainly the hydrolysis of some weak electrolytes, and it is enough to master the hydrolysis equation of weak electrolytes, and there are not many, mainly those kinds, carbonic acid, sulfurous acid, and some weak acids and bases.

The pH value is from large to small.

naoh、naclo、na

conahco3,ch

coonana

sonhso

The stronger the acid corresponding to Nahso, the smaller the pH, and the stronger the corresponding base, the greater the pH. Alkaline (alkaline) salt>neutral" acidic (salt) acidic

In solution, the ions of salt are ionized with the water to form a weak electrolyte.

The process is called hydrolysis of salts. And the ionization balance of water is shifted in a positive direction, thereby promoting the ionization of water. Hydrolysis of salts: salts must be soluble in water, and salts must be able to ionize weak acid ions.

or weak base cations.

1. Substance: In the solution, due to the combination of ions ionized by salt and ions ionized by water to form a weak electrolyte, the ionization balance of water is destroyed, and the ionization balance of water moves to the direction of ionization, showing different concentrations of acidic, alkaline or neutral.

2. Rules: insoluble and not hydrolyzed, only if there is weakness, and no weak is not hydrolyzed; Whoever is weak is hydrolyzed, the weaker the more hydrolyzed, and all weak are hydrolyzed; Who is strong and who is sexual, the same strong is neutral, and the weak is specific; The hotter it is, the more hydrolyzed, and the thinner it is, the more hydrolyzed.

Factors of hydrolytic equilibrium

The most important factor influencing the degree of hydrolysis equilibrium is the nature of the salt itself.

The weaker the acid corresponding to the acid group that makes up the salt, the greater the degree of hydrolysis, the stronger the alkalinity, and the greater the pH; The weaker the alkali corresponding to the cation of the salt, the greater the degree of hydrolysis, the stronger the acidity, and the smaller the pH;

Hydrolysis reaction. and the neutralization reaction are in dynamic equilibrium, and the degree of hydrolysis is very small. The hydrolysis reaction is endothermic.

Salts are dissolved in water, mainly ionized, supplemented by hydrolysis.

Hydrolysis of salt is formed by the combination of ions ionized by salt in solution with H+ or OH- ionized by waterWeak electrolytesreactions.

Salt hydrolysis is essentially salt.

Weak ions (anions of weak acids.

or a weakly alkaline cation.

H+ or OH- ionized with water generates a weak electrolyte (i.e., a weak acid or a weak base), which promotes the ionization of water. The hydrolysis of salt solution is acidic or alkaline, and it is precisely because the weak ions in the salt are ionized with water H+ or OH- to form a weak electrolyte, so that the C (H+) that exists independently in the solution is not equal to C (Oh-).

Hydrolysis

Weak acids and weak alkali salts, the weak acid part binds hydrogen, and the weak alkali part binds hydroxide to form two weak electrolytes, and then compare their ionization constants.

The magnitude of the value of ka, kb (not the degree of hydrolysis), the ionization constant of the weak electrolyte at a temperature (also called the ionization equilibrium constant).

is a fixed value, and this comparison can be used to determine what the salt is and who is strong.

Strong acid and weak alkali salt, we call the weak alkali part weak yang, weak alkali ions combined with hydroxide ions ionized from water.

The ionization equilibrium of water is disrupted, so that the ionization of water moves forward, and as a result, the concentration of hydrogen ions in the solution is greater than the concentration of hydroxide ions, making the aqueous solution acidic.

The above content reference:Encyclopedia – Hydrolysis

In a solution, the ionized ions of salt combine with the hydrogen ions or hydroxide ions ionized by water to form a weak electrolyte, which is called the hydrolysis of salts.

Its essence is that the weak ions (weak acid ions or weak base cations) in the salt combine with the hydrogen ions or hydroxide ions ionized by water to form molecules or ions that are difficult to ionize, thereby destroying the ionization balance of water.

The degree of hydrolysis of salts is generally very small, the hydrolysate products are also very small, and usually do not produce precipitation or gas, so the hydrolysis equation is written without gas and precipitation symbols. The hydrolysis of salts is a reversible reaction, and reversible symbols are generally used except for strong double hydrolysis.

The hydrolysis of polypoly weak salts is carried out in steps and is expressed by the equation of step-by-step hydrolysis of ions.

1) Hydrolysis of weak acid anions.

2) Hydrolysis of weak base cations.

The law of hydrolysis of salts

There is a weak hydrolysis, all weak are hydrolyzed, the weaker the hydrolysis, who is strong and who is neutral.

1) The weak base cations that make up the salt are hydrolyzed, making the solution acidic.

Such as ammonium chloride solution, aluminum chloride solution.

2) Hydrolysis of the weak acid anions that make up the salts make the solution alkaline.

Such as sodium acetate solution, potassium carbonate solution.

3) The weaker the acid (or base) corresponding to the salt, the greater the degree of hydrolysis, and the stronger the alkalinity (or acidity) of the solution.

4) The degree of hydrolysis of the orthocytic ion of the multiple weak acid groups is greater than that of the acid root ions, so the alkalinity of the corresponding positive salt solution is stronger than that of the acid salt solution.

For example, a sodium carbonate solution of the same concentration is more alkaline than a sodium bicarbonate solution.

The hydrolysis of salt is the generation of H+ and OH- from the ionization of strong alkali and weak salts, strong acid and weak alkali salts or weak acid and weak alkali salts with water in solutionWeak electrolytesThe process is called salt hydrolysis.

Whether it is a weak acid or a weak alkali salt, the concentration is reduced when it is diluted, and the degree of hydrolysis increases when the concentration is reduced, and the acid ion is defeated.

or weak base cations.

There are fewer hydrogen, hydroxide ions in the bound water.

Basic Introduction:

1. Definition, the process of ionizing the ions of salt in solution with H+ or OH- ionized by water to form a weak electrolyte is called the hydrolysis of salts.

2. Condition, salt must be soluble in water, and salt must be able to ionize weak acid ions or weak base cations.

3. In essence, the generation of weak electrolytes destroys the ionization of water and promotes the process of ionization of water to move.

4. Regularity, insoluble and not hydrolyzed, there is weak hydrolysis, no inspection of Zheng weak is not hydrolyzed, who is weak and who is hydrolyzed, the weaker the more hydrolyzed, all weak are hydrolyzed, who is strong.

Who's sex (applicable to normal salt, the same as the strong is neutral, the weaker the more hydrolyzed, the hotter the hydrolyzed, the thinner the hydrolyzed.

1. Definition: The reaction of ionized ions from salt to hail (weak acid ions or weak alkali ions) and water ionization or combined into weak electrolytes is called salt hydrolysis.

2. Substance: Generate weak electrolytes to promote the ionization of water. (resulting in C(H+)≠C(OH), and a new equilibrium system was established—the hydrolysis of salts and the balance of sensitivity).

3. The law of salt hydrolysis:

Prepare for the hydrolysis of the weak side, and the absence of weakness is not hydrolyzed; All are weak and hydrolyzed; The weaker it is, the more hydrolyzed; Whoever is strong shows who is sexual, and the same strong shows neutrality.

4. Equation for salt hydrolysis reaction:

Salt + water. = (Reversible.

of) acid + base.