Acute The following substances are not mixtures

It's all a mixture...

The air contains many gases such as nitrogen, oxygen, and carbon dioxide.

Lime water speaks of a calcium hydroxide solution, which is a mixture of calcium hydroxide and water.

Table salt crystals are sodium chloride with crystalline water and are also mixtures.

We know that carbon monoxide is a colorless and odorless gas, and the gas we smell is smelly, because carbon monoxide is a toxic gas, and the main component of pipeline gas is carbon monoxide, which is also mixed with some odorous gas, if the gas leaks, we can deal with it as soon as possible.

Table salt crystals refer to pure sodium chloride, which is a pure substance.

Air contains a variety of components (N2, O2, etc.); Lime water is a solution, and the solution is a mixture (containing solutes and solvents); Pipeline gas is a mixture of various combustible gases (CO, H2).

Table salt, also known as table salt, is one of the most important substances for human survival and the most commonly used seasoning in cooking. The main chemical component of salt, sodium chloride (chemical formula NaCl), is 99% in table salt, and potassium chloride is added to the salt produced in some areas to reduce the content of sodium chloride and reduce the incidence of hypertension.

It's all a mixture, but be aware that there is potassium iodate and the like in table salt, so it also falls under the category of mixtures. Still have questions.

Lime water, solute lime, solution water.

Choose a ice-water mixture, which is ice + water.

Ice and water are both H2O with the chemical formula, which belongs to the same substance.

Therefore, it belongs to pure things.

b is a mixture of iodine and alcohol.

c is a mixture of water, sodium chloride, and other substances.

d is oxygen, nitrogen ......complex mixtures.

A: The molecules in ice and water are H2O, which is pure.

B: Iodine is a mixture of iodine dissolved in alcohol.

C: There is salt in the seawater.

D: Air is a mixture, you know.

A: All are H20 and everything else has impurities.

a. Liquid nitrogen is the liquid state of nitrogen, which is composed of a substance and belongs to pure substance, so A is wrong;

b. Mercury is the common name of mercury, which is composed of a substance and belongs to pure substances, so B is wrong;

c. Lime water is composed of calcium hydroxide and water, which is a mixture, so C is correct;

d. Ice water is composed of a substance of water, which is a pure substance, so D is wrong and therefore selected: C

a. Hydrogen is composed of a substance, which is a pure substance, so the option is wrong B. Oxygen is composed of a kind of Jingtong substance, which is a pure substance, so the option is wrong C. Water vapor is composed of a substance, which is a pure substance so the option is wrong D. The air contains nitrogen, oxygen, carbon dioxide and other substances, which is a mixture, so the option is correct;

Therefore, choose D

a. Hydrogen is composed of a chaotic substance, which is a pure substance; b. Sodium chloride is composed of a substance, which belongs to the pure substance error; c. The air contains nitrogen, oxygen and other substances, which belong to the mixture correct; d. Copper is composed of a substance, which is a pure substance; Therefore, C

a. A substance formed by mixing two or more substances is a mixture, so a statement is correct;

b. Pure substances have fixed composition and properties, and mixtures have no fixed composition and properties, so B is wrong;

c. The mixture is composed of two or more pure substances, so the statement C is wrong;

d. Since the composition of the mixture is not fixed and constant, some of the components and their contents may decrease or increase or remain unchanged, so the D statement is correct

Therefore, b, c

The mixture is a substance composed of a variety of substances, and the substances that make up the mixture may contain two or more compounds, and may also contain elemental substances and may contain compounds For example: the air contains nitrogen, oxygen, carbon dioxide and other substances, mineral water contains water, trace minerals and other substances, and iodized salt contains sodium chloride, potassium iodate and other substances, all of which belong to the mixture Therefore, a, b, c are correct, and d is incorrect

Therefore, choose D

Phosphorus pentoxide is produced by the combustion of red phosphorus with oxygen, and it is a compound, not a mixture.

Its chemical formula is P2O5.

Compounds, elementals, are all pure.

Select C (contains oxygen, nitrogen, carbon dioxide, etc.).

God, what do you mean by chemical reactions, phosphorus pentoxide is a substance produced by the combustion of red phosphorus and oxygen, it is pure, it does not mean that two reactants must produce two products. A chemical reaction is not a mixture of several substances, but a reaction takes place and the substance changes. It's like there are a lot of substances in the air that are mixed, but they don't react with each other, it's still a mixture.

c, there is oxygen, nitrogen, carbon dioxide, etc. in the air Phosphorus pentoxide is a crystal, and its true structure is phosphorus decaoxide.

Red phosphorus is burned in oxygen to form phosphorus pentoxide, which is a chemical change in which red phosphorus and oxygen are consumed to form a new substance, phosphorus pentoxide.