The order of the reaction between acid and base, what is the order of reaction when acid and base sa

Before all the sulfuric acid reactions are completed, does the barium hydroxide react with the sulfuric acid? "

Who said this? The essence is all wrong.

First of all, this experiment is a question of ionic reactions, and there is no question of who comes first and who comes after the matter.

Secondly, the essence should be the reaction of OH- and H+, SO42-, and Ba2+ (which can occur at the same time, and the two reactions are not in the way).

Finally, it is not necessary to divide the specific H+ who ionized it, because in solution, this should be random.

However, if you want to distinguish it, you know that sulfuric acid is a dibasic acid, and the second step of ionization is incomplete, but high school generally defaults to its complete ionization... I do not require mastery of pulling.

Your understanding has no effect on the topic, but this understanding is one-sided.

Because barium hydroxide can be seen as two parts: Ba2+ and Oh-. The mixture of sulfuric acid and hydrochloric acid is seen as three parts Cl-

so42- h+。Its essence is an ionic reaction, i.e., Ba2+ and sulfate reaction, H+ and OH- reaction. Each of them does not disturb each other. OH- in barium hydroxide may react with H+ of sulfuric acid or with H+.

If you're in high school, this pattern can be made clear. It is carried out in the direction of decreasing ion concentration. The weaker the ionization capacity of the product, the first time this reaction takes place.

How to say that? These substances are ionized in water to generate corresponding ions, and then the reaction between ions is not the reaction of barium hydroxide and sulfuric acid, but the reaction of hydrogen ions and hydroxide and sulfate and barium ions.

The essence is ionic reaction, sulfate and barium ion precipitation, hydrogen ion and hydroxide precipitation, and hydrogen ions are distributed and ionized by whom, and the others can be analyzed by analogy.

When acids, bases, and salts are mixed and react with each other, the reaction of acid and base takes precedence over the reaction of acid and salt and alkali and salt, e.g. sodium hydroxide.

The solution drops drop by drop into a mixed solution of hydrochloric acid and copper chloride.

Middle. 1. The OA section indicates that the sodium hydroxide solution first reacts with hydrochloric acid to form sodium chloride.

and water, indicating that there is no precipitation formation, sodium hydroxide solution only reacts with hydrochloric acid to form sodium chloride and water, while copper chloride has not yet reacted; Sodium chloride, copper chloride.

2. The AB section is the reaction of sodium hydroxide solution and copper chloride to form copper hydroxide.

precipitation and sodium chloride, the chemical equation in which the reaction takes place.

CuCl2+2NaOH Cu(OH)2 +2NaCl has blue precipitate;

3. At point C, there is an excess of sodium hydroxide solution, so the solution is alkaline at this time, and the pH of the solution is greater than 7.

Introduction to the relative strength of acids and bases

In the Arrhenius ionization theory, weak acids.

The strength of weak bases is expressed by their dissociation constants. Water can distinguish the strength of these weak acids, weak bases, and strong acids.

strong alkali, then there is no imitation of brother method to distinguish.

For example, in water, strong acids such as HCO4, H2SO4, HCl, etc., cannot be distinguished by dissociation constants. In the aqueous solution, the strong acid is completely dissociated due to the large orange, and the given proton is accepted by H2O, and the difference is generated to H3O+. They are all expressed in the form of H3O+.

For the strong bases in the aqueous solution, they are all manifested in the form of OH-, if there is a stronger base, it will seize the H+ in H2O and produce OH-. Therefore, in the aqueous solution, it is not possible to distinguish the strength of strong acids and strong bases, and water flattens all strong acids to the level H3O+, and all strong bases OH- to the level.

The above content refers to Encyclopedia - Acid-Base Reaction.

My dear, the order of reaction when the acid-base salts meet is that the acid reacts with the base first, producing salt and water. This is because there is an acid-base neutralization reaction between the acid and the base, and when the acid and base are mixed together, they neutralize each other, producing a correspondingly wide grip saddle and water. In this process, acids and bases react rapidly, and the resulting salts and water are the final products.

In chemical experiments, we often use acid-base indicators to determine the acid-base properties of acid-base solutions. When the acid is mixed with the base, we can determine whether the reaction has occurred or not by observing the color change of the indicator. Duan Qiao Hall.

Acid-base salt reaction

It is a common type in chemical reactions. It involves the interaction between three substances, acids, bases, and salts.

acidRefers to compounds or solutions that are capable of releasing hydrogen ions (H+), such as hydrochloric acid (HCl).

AlkaliRefers to compounds or solutions that are capable of releasing hydroxide ions (OH-), such as sodium hydroxide (NaOH).

SaltIt is a chemical residue formed by the reaction of acids and bases, and at the same time releases water molecules.

Acid-base salt reactions typically involve the combination of protons (H+) and hydroxide ions (oh-), which produce water and corresponding salts.

Real-life and industrial applications.

Here are some examples:

Acid-base neutralization reaction:Acid and base reactions can neutralize each other's properties and produce water and salt. For example, hydrochloric acid and sodium hydroxide react to produce water and sodium chloride.

hcl + naoh → h2o + nacl

Acid-base neutralization indicator: The neutralization indicator can display different color changes according to the degree of acid-base reaction and the change of pH value, which can be used for experiments such as acid-base titration.

Pickling: Acids and metal oxides or alkaline substances should be desensitized to remove dirt, rust or deposits from the surface.

Example Explanation:

Example: Which of the following reactions is an acid, which is a base, and which is a salt?

a) nacl + h2o → naoh + hcl

b) koh + hno3 → kno3 + h2o

c) hcl + h2o → h3o+ +cl-

Analysis: a) NaCl + H2O NaOH + HCl: The reaction produces sodium hydroxide (NaOH) and hydrochloric acid (HCl). NaOH is a base and HCl is an acid.

b) Koh + Hno3 Kno3 + H2O: The reaction produces potassium nitrate (Kno3) and water (H2O). Koh is a base and Hno3 is an acid.

c) HCl + H2O H3O+ + Cl-: The reaction produces chloride ions (Cl-) and hydroxide ions (H3O+). HCl is an acid.

Through this example, we can see the substances involved in the reaction of different acids and alkalis and understand their roles in the reaction.

First the acid reacts with the base, then the acid and the salt, the base and the salt.

This is a trapped model determined by their chemical properties.

The H ions in the acid and the OH roots in the base undergo a neutralization reaction to form water (H2O). Acid-base – brine.

For example, HCl NaOH = NaCl H2O

Knowledge development

Acid and base react to form salt and water, and the general expression of acid-base reaction is: HB1+B2HB2+B1.

The acid-base proton theory holds that anything that can produce protons in a chemical reaction is an acid, and anything that can accept protons is a base. The acid-base reaction is actually a proton transfer reaction between an acid and a base, and the direction of its reaction is always the reaction of a strong acid and a strong base, forming a weak acid and a weak base. The essence of an acid-base reaction is the reaction of two conjugated acids and bases with competing protons.

The types of acid-base reactions are broadly classified as follows:

Dissociation of acids: dissociation of strong acids, dissociation of weak acids; dissociation of bases;

Acid-base neutralization reaction:

hydrolysis of weakly salts;

hydrolysis of weak alkaline salts;

Proton auto-reactive reaction of solvents: proton auto-reactive reaction of solvent water, proton auto-reactive reaction of non-aqueous solvent;

Reactions in non-aqueous product solvents.

The acid-base relationship is conjugated, that is, where there is acid, there is alkali, and where there is alkali, there is acid. If you know acid, you will know alkali, and if you know alkali, you will know acid. Acids are called bases; Acids are called bases;

H4 plus NH3 forms a conjugated acid-base pair. In acid-base proton theory. The general expression for acid-base reaction is: HB1+B2HB2+B1.

Thus, in different solvents, the same acids and bases exist in different forms. In the acid-base reaction, different products are finally obtained.

For acid-base neutralization reactions, the products are weak acids and weak bases, so there is no concept of salt in acid-base proton theory, which is the difference between acid-base proton theory and Arrhenius ionization theory.

There is no question of priority or non-priority... When BaCl2 and Ba(OH)2 enter the water, they immediately ionize Ba2+ and Cl-,OH-。。 Dropwise addition of H2SO4 and ionization of H+ and SO42-, Ba2+ and SO42- meet and immediately precipitate.

The same goes for oh- and h+.

H+ and Cl- can coexist in large quantities in stupid early water. So, it's essentially a reaction of ions, not a reaction of the original substance, so your suggestion is problematic.

It can be understood this way. When the electrolyte enters the solution, the ions are ionized, and the ions will react immediately as long as they can react, which is at the same time, that is, if there is a large amount of H+, OH-, Ca2+, CO32-, Mg2+ in the solution, H2O, CaCO3, Mg(OH)2 will be generated immediately.

And it is a simultaneous reaction. When you say preferential, you may be referring to the fact that the generated matter reacts with each other. For example, if FeCl2 is added to Cl2, there are two anti-starvation responses. cl2+2br-==br2+2cl

Because acid-base neutralization is a metabolic decomposition and widening reaction.

Water is generated, and the reaction between acid and salt is generally to form weak acid, the more difficult it is to ionize the product, the faster it is to get out of the reaction system, and the faster the reaction is carried out, so the reaction rate of acid and base.

Change quickly, and give priority to nuclear travel.

The reaction of acid and salt or base is a metathesis reaction in a solution that disrupts the nucleus. According to the conditions of the solution metathesis reaction, the more difficult it is for the product to ionize, the faster it will be detached from the reaction system, and the faster the reaction will proceed.

Why should acid-base neutralization of transfibers precede the reaction of acids and salts? The reaction of acid and base is the reaction of hydroxyl group and hydrogen ion to produce water, and the reaction speed is very fast.

Acid-base reactions, on the contrary, react violently and appear to be a priority reaction.

The reaction between acid and base is actually the reaction of hydroxide and hydrogen ions to produce water, and the reaction speed is extremely fast.

The reaction of acid and base is actually the reaction of hydroxyl groups and hydrogen ions to produce water, and the reaction rate is very fast.

It was found that middle school students were very confused about both of these questions. In any case, to be able to ask questions like this shows that you have really thought about them.

For the first. It should be said that sodium hydroxide reacts with both compounds at the same time. But what we see is that it reacts with sulfuric acid first.

Why, because even if sodium hydroxide reacts with magnesium sulfate first to form magnesium hydroxide, as long as the sulfuric acid is not relied, the two will react immediately and the precipitate disappears. As long as the sulfuric acid is not reactive, the magnesium hydroxide will disappear again. So, you have to know that if you say who reacts first, it must be the same reaction, but for the result, it is the reaction with sulfuric acid first.

Question 2: There is no way to say who will check out first. It's like you don't know what the four bottles of solution are, so you don't know if you see the gas first or see the nuclear precipitate first.

If you're lucky and add one solution to the other three, and two of them have gas out, you're getting potassium carbonate; If there are two precipitates, you get barium chloride. Because you don't know what you're getting first, you can't be sure which one came out first, right? Of course, I'm giving extreme examples, but I can't say that what I'm saying doesn't exist.

Because the essence of acid-base neutralization is the ionization of hydrogen ions and hydroxides and the formation of water-forming molecules, the resulting water will not continue to participate in the reaction, so acid-base neutralization is preferred. Raise.

Example: HCl, NaOH, Na2CO3 react together, assuming HCl reacts with Na2CO3 first, Na2CO3+2HCl=2NaCl+H2O+CO2 gas, and the resulting carbon dioxide will also react with NaOH: 2NaOH+CO2=Na2CO3+H2O.

It can be seen that the total reaction equation of these two reactions is NaOH + HCl = NaCl + H2O, which is acid-base neutralization. This is the reason why metathesis reactions are preferentially neutralized.

The reaction of an acid and a salt or base is a metathesis reaction in solution. Depending on the conditions of the solution metathesis reaction, the more difficult it is for the product to ionize, the faster it will be detached from the reaction system, and the faster the reaction will proceed. Generally speaking, the acid formed by the reaction of acid with salt is weak acid, while the acid-base neutralization reaction produces water.

The weakly formed acid ionizes more easily than water (otherwise it is not called acid anymore). Therefore, the acid-base neutralization reaction rate is greater.

Of course, one of the premises of the above discussion is the exclusion of redox reactions.