How to quickly distinguish whether it is a metathesis reaction or not?

The metathesis reaction can be simply written as: "two exchanges, no change in valence". The reaction in which two compounds exchange components with each other to form two other compounds is called metathesis.

Its essence is: the two substances that undergo 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 is reduced, and the chemical reaction is carried out in the direction of the reduction of ion concentration. Solubility formula: potassium, sodium, ammonium salt, dissolve water quickly, sulfate removes barium, lead, and calcium.

Chloride is insoluble silver chloride, nitrate solution is transparent. None of the mantras are sinking. Note:

Potassium, sodium, ammonium salts are soluble in water; Only barium sulfate, lead sulfate, and calcium sulfate are insoluble in sulfate; Nitrates are soluble in water; Salts not mentioned in the mantra are insoluble in water; soluble formula: potassium, sodium, ammonium salt, nitrate; chloride except silver and mercury; sulfate removes barium and lead; Carbonic acid, phosphate, only soluble potassium, sodium, ammonium. Solubility formula 3: Potassium, sodium, ammonium, nitrate are soluble, hydrochloride is insoluble silver, mercurous; Sulfate is insoluble barium and lead, carbon phosphate is mostly insoluble. Most acids are less soluble, only potassium, sodium, ammonium, barium, solubility, potassium, sodium, nitrate soluble, (potassium salt, sodium salt and nitrate are soluble in water.)

Hydrochloric acid is soluble except silver chloride and mercurous chloride. Speaking of sulfate, there is no room for barium and lead, (the insoluble in sulfate are barium sulfate and lead sulfate.) The rest of the salts, (carbonates, sulfites, phosphates, silicates, and sulfides) are soluble only potassium, sodium, and ammonium, (only the corresponding potassium salts, sodium salts, and ammonium salts are soluble) and finally alkalis, potassium, sodium, ammonium, and barium.

Potassium hydroxide, sodium hydroxide, barium hydroxide, and ammonia are soluble) There are also several microsolubles that can be remembered separately. Solubility formula 5 potassium, sodium, ammonium salt, nitrate, complete dissolution, not difficult, mercuric chloride, silver chloride, barium sulfate and lead sulfate, generate precipitation, remember between hydrosulfates and alkalis, phosphate nitrate carbonate, soluble only potassium, sodium ammonium, soluble only potassium, sodium ammonium, nitrate, strong and weakly insoluble, soluble solubility formula: 7: potassium, sodium, ammonium, salt water, soluble, nitrate, no trace of nitrate, no trace of mercury, chloride in addition to silver, mercury, barium sulfate, lead sulfate, insoluble carbonate, potassium, sodium ammonium, alkali soluble potassium, calcium sodium, barium ammonium Special case:

The solubility of potassium, rubidium, cesium salts of perchloric acid is very small Silver perchlorate has a great solubility, 5570 g l of silver fluoride is soluble in water, and the solubility is large 1800 g l

Metathesis is generally a reaction between acids and alkalis, just see if their positive and negative ions are exchanged. Of course, it really doesn't work, we can only look at the rise and fall of valency, metathesis reaction is not a redox reaction, there is no rise and fall of valency.

Decomposition reaction is a reaction of a substance to produce a variety of species.

The metathesis reaction is a reaction between acids, bases, hydrochloric acids, and alkaline oxides.

General AB+CD-AD+CB

Combining into substances that are difficult to ionize--- precipitation of one substance, and the reaction of one substance to form several substances is called decomposition reaction;

Consists of two compounds exchanging components with each other.

It can be abbreviated as ab cd = ad cb

The essence of the metathesis reaction is that ions in solution combine to form substances that are difficult to ionize (e.g., water). (It can be simply remembered as the reaction that produces two other compounds: alkali salt salt dissolution in brine, called metathesis reaction, and the chemical reaction is carried out in the direction of decreasing ion concentration.)

Its essence is that the metathesis reaction tends to be completed: the two substances that undergo the metathesis reaction exchange ions, insoluble substances or volatile gases, water and precipitate gas water in the aqueous solution, so that the ion concentration in the solution is reduced, and the gas.

A decomposition reaction is a reaction in which one substance produces a variety of substances; Metathesis is a reaction in which two or more substances react to form gas, water, or precipitation.

Decomposition reactions.

The reactant is one.

Metathesis is divided into two types.

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

It can be abbreviated as ab+cd=ad+bc

For example: 2NaOH+MgCl2==Mg(OH)2 +2NaCl has precipitated Na2CO3+2HCl==2NaCl+H2O+CO2 and has gas KOH+HCl==KCl+H2O, which is generated by water.

Do not confuse with displacement reactions, displacement reactions such as.

fe+2hcl==fecl2+h2↑

This is the reaction of the elemental substance with the compound.

Metathesis must be compound-to-compound.