Help with the classification of chemical substances

Na2SO4, KhSO4, NaHCO3, BaSO4 are oxylates.

NaCl is oxygenate-free.

It is mainly to see whether the acid ion has oxygenated elements, and if it contains, it is oxygenated acid, and the corresponding salt is oxygenate. For example, Na2SO4 and SO42 contain oxygenated elements, so they are oxygenates.

In junior high school chemistry, substances are divided into two main categories:

1) Mixture: A substance formed by mixing two or more substances. Note that the emphasis here is on two substances rather than two elements, i.e., a substance consisting of only one element is not necessarily elemental, but may also be a mixture, e.g. oxygen and ozone mixed together.

2) Pure substance: Composed of only one substance, it can be represented by a chemical symbol (chemical formula), such as oxygen (O2).

There are also two categories of pure matter that are classified by the number of elemental kinds, namely:

1. Elemental: It contains only one element, and it is pure (to meet two conditions at the same time), for example, oxygen is a elemental substance composed of only oxygen.

2. Compounds: pure substances composed of two or more elements (two conditions are met at the same time), and then subdivided into acids, bases, salts and oxides; It can also be divided into organic compounds and inorganic compounds according to the classification of composition.

Methods for classifying chemical substances

1. Single taxonomy.

The single classification method is a classification method that classifies the objects separately using only one criterion. A substance containing only one element is not necessarily elemental, such as: a mixture of O and O, a mixture of diamond and graphite, etc., and a pure substance containing only one element is elemental.

2. Cross-taxonomy.

Cross-taxonomy is the application of a number of different single taxonomies to the objects being classified.

3. Tree taxonomy.

Tree taxonomy is the classification of similar things according to certain attributes. The relationship between the whole of the classified object and the sub-type is represented by a tree display.

Chemicals are divided into mixtures and purities.

One. Mixtures: solutions, colloids, suspensions, emulsions, etc.

A mixture is a mixture of two or more substances. The mixture does not have a chemical formula. Without a fixed composition and properties, no chemical reactions occur between the various components of the composition mixture, they retain their original properties.

Two. Purifiers: Elemental (metallic and non-metallic), Compounds (organics: hydrocarbons, hydrocarbons, hydrocarbon derivatives, nutrients; ）。

Pure matter refers to a substance composed of a single substance or a chemical compound, with a fixed composition, a substance with fixed physical and chemical properties, a special chemical symbol, and can be represented by a chemical formula.

1. Mixture: a substance composed of a variety of molecules;

2. Pure substance: a substance composed of only one molecule;

3. Elemental: a pure substance composed of only one element; The shed is in a mess.

4. Compounds: pure substances composed of a variety of element chains;

5. Organic matter: carbon-containing compounds (except carbonic acid, carbonate, and carbon oxides);

6. Inorganics: compounds other than organic matter;

7. Acid: a compound that can accompany the ionization of hydrogen ions by oak;

8. Alkali: a compound that can ionize hydroxide ions;

9. Salt: a compound that can ionize metal cations (or ions equivalent to metal cations) and acid anions.

The classification of chemical substances is made up of pure substances and mixed substances.

Purifiers and mixtures, separation of mixtures.

1) Pure substances are composed of the same substance, the composition is fixed, and there is a unique chemical formula.

The mixture is composed of different substances, the composition is not fixed, and the components maintain their original properties.

(2) Separation of mixtures.

Filtration: It is a method suitable for separating insoluble solids from liquids.

Precautions for filtration operation are "one stick, two low, and three leaning". "One sticker" means that the filter paper is close to the inner wall of the funnel; "Two low" means that the edge of the filter paper is lower than the edge of the funnel, and the filtrate level is lower than the edge of the filter paper; "Three-leaning" means that the beaker is close to the glass rod, the glass rod is close to one side of the three-layer filter paper, and the lower end of the funnel is close to the inner wall of the beaker.

Evaporation method: It is suitable for separating solutes from solvents or removing volatile impurities.

(3) Coarse salt purification process: dissolution, filtration, evaporation and crystallization.

Tree taxonomy: (1) Mixtures: air, solution, alloy.

b) Pure substances: 1Elemental:

Metallic, non-metallic. 2.Compounds:

Oxides, acids, alkalis, salts. Cross-classification: The same substance is classified according to different criteria.

What are chemicalsChemical substances: A chemical substance is any organic or inorganic substance that has a specific molecular identity, including:

a substance produced in whole or in part as a result of a chemical reaction or any compound of a naturally occurring substance;

Any element or non-chemical cluster of atoms.

Chemical substances include elements, compounds (including additives and impurities), by-products, reaction intermediates, polymers, but do not include mixtures, products (agents) and articles.