Dilute acetic acid plus acetic acid how the ionization balance moves

Ionization equation for acetic acid.

is ch3cooh = ch3coo-+h+, because this is a reversible reaction.

So when acetic acid is added, the acetic acid increases, of course, it promotes ionization, so the balance shifts to the right.

And Le Chatre's principle.

Yes: If you change a condition that affects the equilibrium (e.g., concentration, pressure, temperature, etc.), the equilibrium moves in a direction that can attenuate the change.

Therefore, when acetic acid is added to dilute acetic acid, the concentration increases, and the concentration is explained by Le Chatletre's principle as decreasing, so the equilibrium shifts to the right. It has nothing to do with the amount of water.

If you keep adding concentrated acetic acid, first of all, let's assume that when you add it to infinity, it can be regarded as concentrated acetic acid, and without a little water, it is impossible to ionize again. However, no matter how much you add it, there will be water in it, so it will still ionize, and the more you add, the faster it will ionize, so it is impossible to suppress ionization.

For example, there are 100 acetic acid molecules in the original solution, and 3 of them are ionized.

Add glacial acetic acid to increase the number of acetic acid molecules in the solution to 200, and the equilibrium will definitely move in the direction of the positive reaction, but it will not ionize 6 proportionally, and 5 can be ionized, because dilution can promote ionization.

Therefore, when glacial acetic acid is added to the acetic acid solution, the ionization equilibrium shifts to the right, but the degree of ionization decreases.

The addition of acetic acid to dilute acetic acid increases the concentration of reactants, so the ionization balance shifts to the right; However, since the newly added acetic acid is not completely ionized, the degree of ionization decreases.

First of all, after the ionization of acetic acid, CH3COO- and H+ are generated, and when diluted with water, the concentration of hydrogen ions in the solution decreases, because acetic acid is a weak acid, so there is an ionization equilibrium, and the equilibrium moves positively. Although new H+ from the water will enter after dilution with water, the distance between CH3COO- and H+ will increase due to the faster volume change, so the probability of combining to form acetic acid will decrease (that is, the acidity of the solution will always decrease), and the equilibrium will eventually shift to the right.

Questions. But what I'm asking is why the balance is moving in a positive direction.

Ionization equilibrium.

The concentration of water ions is reduced, and the ions are ionized in the forward reaction, and the equilibrium moves in the positive direction according to the principle of Le Chatelier.

Questions. The concentration of the reactant products with water is reduced, why the equilibrium is shifting positively.

Acetic acid is easily soluble in water, but it is a weak electrolyte that is difficult to ionize, and when water is added, the effect on the concentration of acetic acid is relatively small, and the ion concentration decreases relatively large, so the equilibrium moves in a positive direction.

Questions. <>

Then why is the data in the book that the concentration of acetic acid decreases, the degree of ionization decreases, that is, the equilibrium shifts left.

With the addition of water, the acetic acid concentration is reduced.

Acetic acid is ionized by dilution with water.

Bai is moving in the forward direction.

The reason for DU is that the addition of water increases the number of particles in the ZHI solution, and the reaspertoire of the combination of acetate ionization and hydrogen back ion decreases, so adding water can promote ionization.

Ionic compounds and some polar covalent compounds are all ionized into ions in aqueous solution, and no molecules exist, and such electrolytes are strong electrolytes. Strong acids, strong bases, and most salts are strong electrolytes.

At a certain temperature, when the rate of ionization of weak electrolyte molecules into ions is equal to the rate at which ions recombine into molecules, the state in which the concentration of weak electrolyte molecules and ions no longer changes is called the ionization equilibrium of weak electrolyte.

It can be seen from the principle of Le Chatre copy (if you increase a condition that affects the equilibrium (such as concentration, pressure or temperature, etc.), the equilibrium will move in the direction that can weaken this change, here is the concentration), that is, the concentration becomes less, just like the direction of the increase in concentration, so the equilibrium moves in the positive direction, acetic acid is a weak electrolyte, can not be completely ionized, after adding water, it will definitely continue to ionize to achieve an equilibrium state.

Acetic acid is a weak electrolyte, and there is a dynamic reversible equilibrium when ionized in water. Because adding water can effectively reduce the concentration of acetate and hydrogen ions by dilution, so that the probability of recombining into acetic acid molecules by colliding with each other is reduced, so it is conducive to acetic acid ionization, that is, the process moves in a positive direction.

Because acetic acid is a weak electrolyte, the ionization of acetic acid will be promoted by adding water (the hydroxide ions ionized by water will react with the hydrogen ions ionized by the acid), so it will move in a positive direction.

It's not all about bai, if you press the floor.

The H ions ionized by the acetic acid will inhibit the ionization of water, and the reverse version is the reverse movement of water.

It's right. I think it's better to say that in water, the H ions ionized by acid are mainly written as H3O+, that is, they are combined with water, so the H ions ionized by acid after adding water are more combined with H2O.

In fact, for acetic acid, the thinner the concentration, the greater its pH.

For ionization of weak electrolytes, keep in mind that the thinner the solution, the more ionized it is, and the hotter it is, the more ionized.

Acetic acid (CH3COOH) can only be partially ionized into CH3COO- and H+ in water, but it can be completely ionized by the following methods:

1.Add a strong alkali solution: add a sufficient amount of strong alkali (such as sodium hydroxide NaOH) solution to acetic acid, because the strong alkali has strong alkalinity, it will react with H+ in acetic acid to generate water and acetate ions (CH3COO-).

At this time, as the acetic acid is gradually neutralized, the concentration of AC- macrofibrillation also gradually increases, and finally complete ionization can be achieved.

2.Increasing the temperature or adding a catalyst: Increasing the temperature or adding a catalyst (e.g., concentrated sulfuric acid) can promote the ionization process of acetic acid, causing more acetic acid molecules to react with water molecules, thereby increasing the concentration of CH3COO-.

3.Electrolyte solution: dissolve acetic acid in electrolyte solution, such as silver nitrate (AGNO3), hydrochloric acid (HCl), etc., due to the reaction with acetic acid, it will promote the ionization process of acetic acid and make it completely ionized.

It should be noted that the above methods need to understand the properties of the sample and the required operation steps before the experiment, so as to ensure the accuracy of the experimental results with rolling matter. At the same time, it is also necessary to pay attention to safety during the experiment to avoid chemical exposure** and inhalation of harmful gases.

When diluted with water, the degree of ionization should continue to increase, and finally it is close to 100%, but its conductivity should rise first and then decrease with the amount of water added, because the main effect of conductivity is different at each stage, and the main influencing factor that rises first is the degree of ionization of acetic acid in solution.

For example, if I drop a drop of vinegar into a lake, the degree of ionization must be very large, but at this time its conductivity is very low, so it can be said that it should be considered the conductivity of water.

Ionization results in the loss of electrons after the collision of subatomic particles, collisions with other atoms, molecules and ions, or through interaction with light. Heterocleavage and heteroatom substitution reactions can lead to the formation of ion pairs. The ionization energy undergoes the internal conversion process of radioactive decay and excites its energy to the inner electrons of the nucleus to eject it.

With the addition of glacial acetic acid, the balance shifts to the right [this conclusion can be explained by Le Chatre's principle].

Glacial acetic acid is added to increase the concentration of reactants, and the reaction proceeds in the direction of decreasing the concentration of this reactant, that is, the equilibrium shifts to the right.

Add water and shift the balance to the right [this conclusion can be explained by the effective collision theory].

Most of the reactions require the reactant molecules to effectively collide with each other, dilute with water, and reduce the concentration of the aqueous solution of the weak electrolyte (your teacher did not take into account that the concentration of H+ AC- will also decrease, and it is more complicated to judge by Le Chatre's principle), which reduces the chance of ions [colliding to form molecules], so that the degree of ionization increases, that is, the equilibrium shifts to the right.

Therefore, it is summarized as the [dilution law] of the thinner the more ionized, which is proved as follows:

Let the concentration of acetic acid solution be c and the degree of ionization

hac===h+ +ac-

The starting concentration is c0 0

Equilibrium concentration c-c c

Ionization constant k=[h+][ac-] hac]=(c)2 [c(1-)c2(1-)

When %, 1- 1

So k=c 2

k c) can be seen when % is k=c 2,c(h+)=c ) 2= (k*c).

The degree of ionization is inversely proportional to the square of the concentration C, that is, the thinner the solution, the greater the ionization of the weak electrolyte, which is called the law of dilution.

The above is found on the Internet, I think it is more useful, and this glacial acetic acid (pure acetic acid can form an ice-like solid when it is below) can be used to explain the concentrated solution of acetic acid.

Glacial acetic acid is added to the acetic acid solution and the ionization equilibrium will shift to the right.

The following ionization equilibrium is present in the acetic acid solution:

With the addition of glacial acetic acid, the concentration of CH COOH increases, and according to the principle of Le Chatelier, the concentration of reactants increases, and the equilibrium will shift to the right.

Le Chatre's principle.

Also known as the chemical equilibrium movement principle, the main content is that in a reaction that has reached equilibrium, if one of the conditions that affect the equilibrium is changed (such as temperature, pressure, and the concentration of chemicals participating in the reaction), the equilibrium will move in the direction that can weaken the change.

Dilution promotes ionization, which means that the degree of ionization increases, but the degree of ionization has nothing to do with the equilibrium shift, please be aware of this.

Let me take another example, 2NH3=N2+3H2

NH3 is charged during equilibrium, and the balance moves positively, and the NH3 conversion rate decreases.

However, when the volume is expanded during equilibrium, the equilibrium also moves in a positive direction, while the NH3 conversion rate increases.

It's like your acetic acid solution, dilution is a case of expanding the volume, the equilibrium is moving forward, and the HAC conversion rate is increased, that is, the ionization degree is increased.

If HAC is added, it is equivalent to the first case of NH3 above, which moves in a positive direction, but the HAC conversion rate decreases, that is, the ionization degree decreases.

The two ways of changing the balance are not the same.