What are the conditions under which the metathesis reaction takes place, and what is the solubility

The essence of metathesis reaction is that two substances that undergo metathesis reaction exchange ions with each other in an aqueous solution.

Conditions for metathesis reaction to occur: (the following conditions are met at the same time) 1) reactants: must be soluble (including soluble acids).

2) Product: precipitation, gas or water generation.

These are metathesis reactions:

Basic oxide + acid – salt + water.

For example: cao+2hcl=cacl2+h2o]base + acid--- salt + water.

For example: NaOH+HCl=NaCl+H2O] type of metathesis reaction Salt (dissolved in water or dissolved in acid) + acid --new salt + new acid e.g.: BaCl2+H2SO4=BaSO4 +2HCl] salt (soluble) + base (soluble) --new salt + neoalkali e.g.:

Na2SO4 + BA(OH)2 = BaSO4 +2NaOH] salt (soluble) + salt (soluble) – two new salts.

For example: Na2SO4+BACl2=2NaCl+BaSO4] is summarized as: ab+cd=AD+BC

The solubility table is the solubility of common acids, alkalis and salts in water, which is soluble, slightly soluble and insoluble.

Metathesis reactions occur under the conditions of: gases, weaker acids or bases, or precipitation production!

Upstairs is the correct solution.

You assume that there is a small part of the reaction, but the product is difficult to ionize, and it is out of solution. According to the Le Château principle, the reaction will proceed in a positive direction and will eventually be complete.

It is enough to produce substances that are more difficult to ionize than reactants.

1. Introduction: Metathesis reaction is a reaction in which two chemical compounds exchange components with each other to generate two other compounds, the essence of which is that the two compounds that occur metathesis reaction in the reaction system are mostly aqueous solution exchange ions, and the most common combination into a precipitate, gas or weak electrolyte that is difficult to ionize is water, so that the ion concentration in the reaction system is reduced, and the chemical reaction is carried out in the direction of the reduction of ion concentration.

2. Concept: There is a precipitate or gas or a weak electrolyte in the product. This is a macroscopic phenomenon that can be observed, and the formation of precipitates, gases, or weak electrolytes will reduce the concentration of ions in the solution and the reaction will proceed in the forward direction.

Characteristics of metathesis reaction: compound reactants and products are compound exchanges, reactants exchange with each other, component valence remains unchanged, and reactant products and products remain unchanged.

3. Essence: According to the concept and reaction conditions for microscopic analysis and metathesis reaction is only the mutual exchange of Ninzhao's ion components between the two compounds, the ions in the reactants before the reaction are coexisting in a certain proportion, the valence of each element before and after the reaction remains unchanged, the type and number of ions remain unchanged, but with the continuous occurrence of the reaction, the concentration of freely moving ions in the solution continues to decrease. The metathesis reaction is the inter-ionic reaction of electrolytes in solution.

1. Conditions for the occurrence of metathesis reaction: the two substances that undergo metathesis reaction can exchange ions in aqueous solution and combine into substances that are difficult to ionize (precipitation, gas or weak electrolyte).

2. Basic oxide + acid: the acidity of the acid is strong (such as HCl, H2SO4, HNO3, etc.), and the reaction can occur.

3. Acid + alkali (neutralization reaction): when the acid and alkali are weak, no reaction occurs.

4. Acid + salt: strong acid to weak acid; There is precipitation after the exchange of ions; strong acids react with carbonates; A reaction can occur when one condition is met.

5. Alkali + salt: strong alkali reacts with ammonium salt; Both reactants are soluble, and there are one of three after the exchange of ions: precipitation, water, and gas; A reaction can occur when one condition is met.

6. Salt + salt: both reactants are soluble, and there is one of the three of precipitation, water and gas after the exchange of ions, and the reaction can occur if one condition is met.

The conditions for the metathesis reaction are that there is a precipitate in the product or there is gas or water.

For a long time, it has effectively guided scientific experiments and production practices. It has been shown through practice that a substance or resalt can be precipitated in the reaction due to temperature difference or concentration, and metathesis reaction can also occur.

The 2005 Nobel Prize in Chemistry was awarded to three scientists for their achievements in the study of olefin metathesis reactions.

Requirements for the types of reactants and products: Reactants and products are two kinds of compounds. The combined form of the change of the substance before and after the reaction:

That is, whether the reactions "exchange components with each other". From the perspective of valency change, in the process of metathesis reaction, only the compounds exchange components with each other, and the valency of the elements does not change, such as acid-base reaction, salt-salt reaction, etc.

Acid-base neutralization reaction, law: acid-alkali brine water, conditions: at least one of the acids and bases is soluble.

Usually acids are soluble acids, and bases can be either soluble or insoluble. Basic oxides react with acids, law: metal oxides (basic oxides) acids salt water auspicious branches, conditions:

Acids should be soluble in water and are generally strong acids.

The reaction between alkali and salt, law: alkali salt suspicion liquid Xinmin new salt new alkali, conditions: The alkali and salt participating in the reaction must be soluble; At least one of the new salts and new alkalis generated is a precipitate.

The conditions under which the metathesis reaction occurs.

According to the conditions under which the metathesis reaction tends to be completed, certain conditions are required for the metathesis reaction to occur. The following analyzes the conditions for the occurrence of metathesis reaction according to the following four types of reactions from the aspects of reactants and products. The conditions for the metathesis reaction of acids, alkalis and salts in the solution are precipitation, gas release, or water formation.

1) Acid + Salt — New Acid + New Salt.

The acid in the reactant must be soluble, and at least one of the substances in the product is gas or precipitate or water.

For example: 2HCl CaCO3=CaCl2 H2O CO2

2) Acid + Alkali – Salt + Water.

At least one of the reactants is soluble.

For example: H2SO4 Cu(OH)2=CuSO4 2H20

3) Salt + Salt — Two new salts.

Both salts in the reactants are soluble, and at least one of the two salts resulting from the reaction is insoluble.

For example: Na2SO4 BACl2=2NaCl BaSO4

4) Salt + alkali — new salt + new alkali.

The reactants are generally soluble, and at least one of the products is a precipitate or gas (only ammonia salts react with alkali to form gas).

For example: 2NaOH CuSO4=Na2SO4 Cu(OH)2 ; naoh＋nh4cl=nacl＋nh3↑＋h2o

Fe(OH)3 does not react with NaCl.

Note: Whether acid + alkaline oxide - salt + water and alkali + acid oxide - salt + water are metathesis reactions is still inconclusive, and it is recommended to avoid the above two reactions when answering the questions.

Conditions under which the metathesis reaction occurs: (the following conditions are met at the same time).

1) Reactants: must be soluble (including soluble acids).

2) Product: There must be precipitation or gas or water or weak electrolyte (e.g., NaAC+HCl=NaCl+HAC).

The essence of the metathesis reaction is that the two substances that undergo the metathesis reaction exchange ions with each other in the aqueous solution, and combine into substances that are difficult to ionize--- precipitation, gas, and water, so that the ion concentration in the solution decreases, and the chemical reaction is carried out in the direction of the reduction of ion concentration. The conditions under which the metathesis reaction occurs.

1) Reactants: must be soluble (including soluble acids) (2), products: precipitate, gas or water generation.

Metathesis reaction is a reaction in which two compounds exchange components with each other to generate two other compounds, the essence of which is that the two compounds that undergo metathesis reaction exchange ions in aqueous solution and combine into a precipitate, gas or weak electrolyte (the most common is water) that is difficult to ionize, so that the ion concentration in the solution is reduced, and the chemical reaction is carried out in the direction of the decrease in ion concentration.

Metathesis reaction is a reaction in which two compounds exchange components with each other to produce two other compounds, which is one of the four important types of basic chemical reactions, and it is also the core content of the reaction between acids, bases and salts.

That is: ab+cd=ad+cb

There is precipitation in the product or there is gas or water. This is a macroscopic phenomenon that can be observed, and the formation of precipitation, gas, or water will reduce the concentration of ions in the solution and the reaction will proceed in the forward direction. Characteristics of metathesis reactions:

Compound reactants and products are compounds; phase exchange, in which reactants exchange components with each other; The valence does not change, and the valence of the reactants and products does not change.