What is material coexistence? For example, what happened to the two substances?

What we usually call the coexistence of matter is strictly the coexistence of substances (or particles) in large quantities, that is, no chemical reactions occur.

In high school, it is believed that substances or particles can coexist in large quantities as long as they do not have chemical reactions.

There are four common conditions that can generally react:

1.Metathesis reaction can occur.

That is, any one of the three that can generate precipitation, gas, and substances (weak electrolytes) that are difficult to ionize is capable of reaction, such as silver ions and chloride ions can form precipitates or hydrogen ions and hydroxide ions can form water.

2.Redox reactions can occur.

Such as between ferric ions and iodine ions.

3.A thorough dihydrolysis reaction can occur.

In the second year of high school, you can learn) such as aluminum ions and carbonate ions.

4.Complexation reactions can occur.

For example, ferric ions and thiocyanide roots (SCN-) form Fe(SCN)3 and so on.

The coexistence of substances generally refers to the fact that two substances and solutions want to mix without reacting. For example, if we put NaCl and NaOH into water at the same time, the two substances cannot react, that is, they can coexist; And if we put NaCl and AgNO3 into the water at the same time, they can react, and then they can't coexist.

Refers to the ability of two or more substances to exist in a particular environment at the same time.

However, we were often exposed to the problem of ion coexistence in high school. Let's take a case of ion coexistence.

Sulfate, chloride ions, and sodium ions can coexist in acidic solutions, because these ions can exist stably under acidic conditions and will not react to form water, gas, or precipitation.

The commonality of matter is the four-dimensional space-time of the existence of matter. Electrons rotate in one direction, in which gravity is determined by gravity, and lasers are not affected by the earth's gravity to transmit energy to space, and are formed by all the matter in the space and exist in it.

The formation of material space-time is formed by the extended form of multiple repeats. The common part of time is still time, and the two independent components represent the existence of electromagnetism. The public form, on the other hand, is the intrinsic nature of matter.

If orthogonal it is equal to zero. This space is mainly found between the nucleus and the electrons outside the nucleus. It is also a kind of space-time, but it is not a four-dimensional space-time.

Conceptual analysis

Everything is not isolated, it has internal causes and external causes, and the main internal causes determine the nature and direction of development. For example, if you plant melons, you will get melons, and if you plant beans, you will get beans. You can't get melons when you plant beans, and you can't get beans when you plant melons.

Due to the different internal basis, the egg hatches the chick at the appropriate temperature, and the temperature cannot make the stone egg hatch the chick, because the internal basis is different.

At the same time, the outer edge can only function through internal causes. Sunlight and water, through the photosynthesis of plants, can promote plant growth. In short, in the development process of anything, internal causes and external edges exist at the same time, and both are indispensable.

The common denominator of matter is that they are all made up of molecules and atoms.

The electron manifests a negative charge moving in the opposite direction of the positive charge.

The gravitational force is determined by the mass, and the greater the mass, the greater the gravitational force.

Light has wave-particle duality, which means that light has the properties of both mechanical waves and particles, so to speak, light is a particle with almost no mass, and without mass, it is not attracted by the gravitational pull of the earth.

When you reach a certain level of knowledge, you can find the answer on your own and brush up on high school physics.

Methods of coexistence or not:

The essence of the metathesis reaction is that two compounds exchange components with each other to form two new compounds, so if one of the following conditions is met, the ions in the same solution will react, that is, the ions cannot coexist in large quantities in the solution. Swim slippery.

1) Precipitation: such as Ag+ and Cl-, Ba2+ and SO42-, Ca2+ and CO32-, Cu2+ and Oh-, etc., can not coexist in large quantities.

2) Gases generated: such as H+ and CO32-, HCO3-, NH4+ and OH-, etc., cannot coexist in large quantities.

3) Generate water: such as H+ and OH- cannot coexist in large quantities.

4) There may be additional conditions that make stupid, such as the solution is colorless and transparent, pH=L (acidic solution), pH=14 (alkaline solution), etc. When judging whether ions can coexist, Shenyuan should first see the prerequisites of the test questions and then analyze the interaction between ions.

If you can react, you don't coexist.

It's usually an ion coexistence problem. There are several reactions that may occur:

Raw eggplant segments are precipitated, such as AGCL, CaCO3, BaSO4, Cu(OH)2, Fe(OH)3....Trembling before the reputation....Repentance.

Gases such as CO2, H2S, SO2, NH3 ...... generatedFormation of refractory ionization substances: such as CH3Cooh

Redox reaction occurs: Fe3+ cannot coexist with I-, H+, No3-, Fe for Ding Duo Gu Ying, and Bifansil 2+.

Complexes generated: Fe3+, SCN-

Double hydrolysis: Fe3+ and CO32-, HCO3- double hydrolysis, Al3+ and CO32-, HCO3-, AlO2-, S2- double hydrolysis.

No chemical reaction occurs, and no gases, leads, dates, and precipitation are generated.

1) Due to the dismantling and decomposition reaction of Huai trace, ions cannot coexist in large quantities. State Bu.

1. There are gases generated: such as CO32-, SO32-, S2-, HCO3-, HSO3-, HS-, etc

It is not possible to coexist in large quantities.

2 There is precipitation generation. Such as ba2

ca2mg2

AG etc. cannot be compared with SO42-, CO32-,

po43-

No chemical reaction occurs, and there is no formation of gas and precipitation in the lead elimination period.

a) Due to the metathesis reaction, ions cannot coexist in large quantities.

1. Gas production: such as CO32-, SO32-, S2-, HCO3-, HSO3-, HS-, and other volatile weak acids cannot coexist with H in large quantities.

2 There is precipitation generation. Such as Ba2, Ca2, Mg2, Ag and other excitants can not be compared with SO42-, CO32-, PO43-

This problem is not difficult, mainly metathesis reactions, such as CaCO3, MgCO3, and Mg(OH)2 precipitation generation, does not involve redox reactions, and you need to judge the color of the solution, so you need to memorize the color of common salt solutions, for alkali metals and alkaline earth metals The general compounds are colorless, and most of the ions of transition metal elements are colored, which is related to the transition of its d electrons, and needs to be mastered. Chemistry scores will naturally improve, come on!

d Copper ions have a color and are excluded first.

Magnesium hydroxide is insoluble, so in a strong alkali environment, magnesium ions cannot exist in large quantities, excluding b.

Calcium carbonate is insoluble, so in a strong carbonate environment, calcium ions cannot exist in large quantities, excluding C.

A is the correct answer.

The correct answer is A.

Item B produces magnesium hydroxide precipitation.

Item C produces calcium carbonate and magnesium carbonate precipitates.

The copper chloride in item D is green and the solution is not colorless.

Solving the problem of coexistence of chemical substances. It is hydrochloric acid, potassium nitrate, sulfuric acid, sodium chloride.

The answer is a. Because B will form a white magnesium hydroxide precipitate, and C will form a white calcium carbonate precipitate. The solution of d is blue-green.