How solutions are formed and how they are distinguished

Formation of solutions.

1. Solution: one or several substances are dispersed into another substance to form a homogeneous.

1. A stable mixture, called a solution.

Uniformity: the properties, concentration, density, color, etc. of each part are the same.

Stability: When the water does not evaporate and the temperature does not change, the solution does not stratify and precipitate.

Solute: A substance that is dissolved (can be gases, liquids, and solids).

Solvents: substances that can dissolve other substances (common solvents: water, alcohol, gasoline; When there is water in the solution, water is generally used as a solvent; ）

2. Able to distinguish solutes and solvents in solution (such as: iodine wine, sugar water, normal saline, aqueous solution of potassium permanganate, lime water);

3. Know the quality relationship between solution, solute and solvent (solution quality, solute quality, solvent quality) and mass ratio.

Dissolution can be classified according to its form, which can be divided into solid solution (such as alloy, etc.), liquid solution (solution in the usual sense) and gaseous solution (any two non-reactive gases will be mixed evenly).

According to whether it is saturated or not, it can be divided into saturated solution, supersaturated solution and unsaturated solution.

According to the type of solvent, it can be divided into aqueous solution, non-aqueous molecular solution, and non-aqueous aqueous aprotic solvent solution.

According to the concentration classification, it can be divided into concentrated solution and dilute solution.

According to the classification of solutes, it can be divided into acid solutions, alkali solutions, salt solutions, organic solute solutions and so on.

According to whether the solute is an electrolyte or not, it can be divided into electrolyte solution and non-electrolyte solution.

Microscopic formation process of solution: the process of diffusion of solute molecules (or ions) into a solvent under the action of solvent molecules, and the solute is uniformly dispersed in the solvent in the form of molecules or ions in the solution.

Note: 1. Both.

1. A stable liquid is not necessarily a solution, such as water.

2. The solution is not necessarily colorless, such as copper sulfate solution.

is blue, ferrous chloride.

The solution is light green.

3. The undissolved part of the solution cannot be regarded as a solute.

4. Solution quality, solute mass, solvent cracking volume, solution volume≠ solute volume, solvent volume.

The purpose of the solution1. Many reactions are carried out in solution, which can speed up the rate of reaction.

2. The solution is of great significance to the physiological activities of animals, plants and people.

The nutrients in the food ingested by animals must be digested and turned into a solution before they can be absorbed. Plants get all kinds of nutrients from the soil, which also need to be turned into a solution so that they can be absorbed by the roots.

The above content refers to: Encyclopedia - Solution.

1.Solubility: A dissolved substance (e.g., salt and water are used to prepare salt salt, which is a solute)2Solvent: A substance that dissolves other substances (e.g. salt and water are used to prepare salt water, water is the solvent).

3.When two solutions are miscible with each other, the one with a large amount is generally called a solvent, and the one with a small amount is called a solute.

4.When two solutions are miscible with each other, if one of them is water, water is generally referred to as a solvent.

5.Solids or gases dissolve in liquids, and liquids are usually called solvents.

The formation of a solution is the mixing of two or more substances to form a uniform and stable dispersion system.

Solution refers to a homogeneous and stable mixture of one or more substances dispersed in the form of molecules or ions in another substance. The solution can be divided into gaseous solution and solid solution according to the different aggregation forms, and their components include solutes and solvents, among which the dissolved substances are called solutes, and the substances that can dissolve other substances are called solvents.

solution shouts old concentrationThe concentration of the solution is expressed as a percentage of the mass of the solute to the mass of the total solution, which is the percentage concentration of the mass, expressed by the sign %. The formula for calculating the concentration of the solution is that the mass percentage concentration of the solution = the mass of the solute 100% of the mass of the solution. For example, 10% potassium chloride injection, that is, 100 grams of this solution contains 10 grams of potassium chloride.

Because the specific gravity of water is 1,100 grams, a solution is basically equal to 100 milliliters.

The above content refers to: Encyclopedia - Solution.

The knowledge points of the formation of chemical solutions are as follows:

1. Solution. 1) The concept of solution: a homogeneous and stable mixture formed by the dispersion of one or several substances into another substance, which is called dissolution.

The liquid loses the oak. 2) The basic characteristics of the solution: a mixture of uniformity and stability.

Note: The solution is not necessarily colorless; The solute can be solid, liquid, or gaseous; Water is the most commonly used solvent; The mass of the solution = the mass of the solute + the mass of the solvent The volume of the solution The volume of the solute + the volume of the solvent; Name of the solution: Solvent solution of solute (e.g

Alcohol solution of iodine iodine).

2. The judgment of solute and solvent is water, water is solvent, liquid is soluble in liquid, anhydrous, and more is solvent.

3. Saturated solution and unsaturated solution.

1) Judgment method: see if there is insoluble matter or continue to add the solute to see if it can be dissolved.

2) Conversion between saturated and unsaturated solutions.

3) The relationship between concentrated and dilute solutions and saturated unsaturated solutions: saturated solutions are not necessarily concentrated solutions; An unsaturated solution is not necessarily a dilute solution, such as a saturated aqueous solution of lime is a dilute solution; At a certain temperature, a saturated solution of the same solute must be denser than its unsaturated solution.

4) Exothermic and endothermic phenomena during dissolution.

Dissolution and endothermy: such as ammonium nitrate dissolution; Dissolution and exothermy: such as sodium hydroxide dissolution, concentrated sulfuric acid dissolution; Dissolves without obvious thermal phenomena: such as NaCl.

The main starting point is the concept of solution.

1. The solution is composed of at least two substances.

1. A stable mixture in which the dispersed substance (solute) is dispersed in molecules or smaller particles in another substance (solvent).

2. The two essential elements of the solution are: solvent and solute

3. The solution is a mixture.

4. The solution must be uniform and stable.

For example, H2O is pure, so it is not a solution.

The liquor that is drunk is a homogeneous and stable mixture of water and ethanol, so it is a solution.

I don't know how to ask.

Solution: (1) Whether a substance is dissolved or not depends on the nature of the substance on the one hand; On the other hand, it is also related to the nature of the solvent;

2) The size of the solubility depends on the properties of the substance itself, and secondly, it is also related to temperature, pressure and solvent; In order to verify the influence of temperature on solubility, the quality of the solvent needs to be controlled under the premise of selecting the solute and solvent type.

3) The solubility of the substance is related to the nature of the solvent, iodine is not easy to dissolve in water, but it is easy to tolerate organic solvents, so when washing iodine sprinkled on clothes, organic solvents, such as alcohol or gasoline; The principle of washing and cleaning the oil stain is that the surfactant in the washing cleans the oil stain is dispersed in the water with fine droplets to form an emulsion and clean the oil stain

Therefore, the answer is: (1) the nature of solute and solvent;

2) temperature, amount of solvent;

3) soak the spotted part in alcohol (or gasoline); Alcohol removes spots, which is a solution formed by the stain being dissolved in alcohol; Washing and cleaning to remove oil stains is the surfactant in the cleaning to disperse the oil stains in the water with fine droplets, forming an emulsion