Definition of chemical reaction, what is the definition of chemical reaction

1 Metals, Oxygen, Metal Oxides.

Many metals can be directly combined with oxygen. For example, when the common metal aluminum comes into contact with air, a dense oxide film can be immediately formed on its surface, which can prevent the inner layer of aluminum from being oxidized.

2 Non-metallic oxygen Non-metallic oxides.

When ignited, many non-metals can be burned in the air.3 Metals Non-metals Oxygenate-free.

Many metals can be directly synthesized with non-metallic chlorine, sulfur, etc. to form anoxate.

4 Hydrogen Non-Metallic Gaseous Hydride.

Due to the relatively stable nature of hydrogen, the reaction generally needs to be carried out under ignition or heating conditions.

5 Basic oxide water alkali.

Most basic oxides cannot be combined directly with water. To judge whether an alkaline oxide can be directly combined with water, the general method is to look at the solubility of the corresponding alkali, and if the corresponding alkali is soluble or slightly soluble, the alkaline oxide can be directly combined with water.

The corresponding alkali is insoluble, so the alkaline oxide cannot be directly combined with water. For example, Cuo and Fe2O3 cannot be directly combined with water.

6 Acidic oxide water oxygenated acid.

With the exception of SiO2, most acidic oxides can be directly combined with water to form oxygenated acids.

7 Basic oxides, acidic oxides, oxygenates.

Most basic and acidic oxides can carry out this reaction. The stronger the alkalinity corresponding to the alkaline oxide, and the stronger the acidity corresponding to the acidic oxide, the easier the reaction will be.

8 Ammonium ammonium ammonia.

Ammonia is easily acidified to synthesize ammonium salts.

It refers to the reaction of two or more substances to produce a new substance, in which part of the reaction is redox and part is non-redox. In addition, not all chemical reactions are exothermic reactions.

The reaction in which several reactants form a product is a chemical reaction.

It is a reaction (combination) in which two or more substances produce a new substance

reaction)。Some of these reactions are redox reactions and some are non-redox reactions.

In addition, chemical reactions generally release energy.

Note: Not all chemical reactions are exothermic reactions.

Chemical reaction: a+b=ab

The reaction in which two or more elemental or compound reactions to form one compound is called a chemical reaction C+O2=CO2

s+o2=so2

cao+h2o=ca(oh)2

n2+3h2=2nh3

nh3+h2o+co2=nh4hco3

2cu+o2+h2o+co2=cu2(oh)2co3

Definition of chemical reaction: Chemical reaction refers to the reaction of two or more substances to form another substance.

The characteristics of the chemical reaction are: the reactants are two or more kinds, and the product is one. Some of these reactions are redox reactions and some are non-redox reactions. In addition, chemical reactions generally release energy.

Note: Not all chemical reactions are exothermic reactions.

Characteristic: Changeable one.

Expression: a+b=ab

There are four basic types of chemical reactions: compounding, decomposition, displacement, and metathesis.

Chemical reaction: A reaction in which two or more substances produce another substance, called a chemical reaction.

a+b=c decomposition reaction: a chemical reaction in which two or more other substances are generated from one substance, which is called a decomposition reaction.

a=b+c displacement reaction: The reaction in which one element reacts with another compound to form another element and compound is called a displacement reaction.

a+bc=ac

bMetathesis reaction: The reaction in which two compounds exchange ions with each other to form two other compounds is called metathesis reaction.

ab+cd=ad+cb

A chemical reaction is a reaction in which two or more substances react to form a new substance.

What is Chemical Reaction?

Chemical reaction and decomposition reaction are both basic types of chemical reactions, chemical reaction refers to the reaction of two or more substances to participate in the reaction to produce one substance; A decomposition reaction is a reaction in which one substance reacts to produce two or more substances.

Definition of Chemical Reaction:

The characteristics of the chemical reaction are: the reactant is two or more kinds, and the product is a kind of so: the chemical reaction refers to the reaction of two or more substances to produce another substance.

Oxidation reactions. 1.The chemical reaction between a substance and oxygen is a type of oxidation reaction; Oxygen can react chemically with many substances.

The function of gaining electrons is called reduction. Oxidation in the narrow sense refers to the combination of substances and oxidation; Reduction refers to the action of a substance losing oxygen. The oxidation value increases during oxidation; The oxidation value decreases when reduced.

Oxidation, reduction both refer to reactants (molecules, ions, or atoms).

Oxidation is also known as oxidation or oxidation reaction. When organic matter reacts, the effect of introducing organic matter into oxygen or removing hydrogen is called oxidation; The action of introducing hydrogen or losing oxygen is called reduction. The oxidation of a substance that reacts slowly with oxygen and slowly heats up without emitting light is called slow oxidation, such as metal rust, biological respiration, etc.

2.When the general substance oxidizes with oxygen, it is exothermic, and some may absorb heat such as the reaction between nitrogen and oxygen. In electrochemistry, the anode is oxidized and the cathode is reduced.

3.According to the different oxidants and oxidation processes, the oxidation reaction is mainly divided into air (oxygen) oxidation and chemical reagent oxidation. Chemical reagent oxidation has the advantages of good selectivity, simple process, convenience and flexibility, etc., in the field of pharmaceutical and chemical industry, due to the small tonnage of the product, the chemical reagent oxidation method is mostly used.

4.The oxidants used in the oxidation of chemical reagents include inorganic oxidants and organic oxidants, inorganic oxidants include: metal oxides, metal salts, nitric acid, sulfuric acid, sodium chlorate, ozone, hydrogen peroxide, etc.; Organic oxidants are generally tempered oxidants, including nitros, nitros, peroxyacids, and complex oxidants formed with inorganic oxides.

5.A reaction in which the valency of the elements contained in a substance decreases. For example, the hydrogen element in hydrogen has a valency of 0 and an oxidation reaction occurs.

6.Reaction with loss of electrons (increased valency).

A reaction in which two or more substances react to produce a new substance.

According to the first three networks, it can be known that the chemical reaction refers to the reaction of two or more substances to form a new substance. Some of these reactions are redox reactions, such as the combustion of iron in oxygen. Some are non-redox reactions, such as the reaction of calcium oxide with sulfur trioxide.

In addition, chemical reactions generally release energy.

Main types: 1. Metal + oxygen Metal oxides, many metals can be directly combined with oxygen. 2. Non-metal + oxygen Non-metallic oxides are ignited, and many non-metals can be burned in oxygen.

3. Metal + non-metal anoxate, many metals can be directly synthesized with non-metal chlorine, sulfur, etc. 4. Hydrogen + non-metallic gaseous hydride, because the nature of hydrogen is relatively stable, the reaction generally needs to be carried out under the conditions of ignition or liquid stuffiness. Nao.

It refers to the reaction of two or more substances to produce a new substance (note that there is only one type of product).

Some of these reactions are redox reactions and some are non-redox reactions.

In addition, chemical reactions generally release energy.

Note: Not all chemical reactions are exothermic reactions.

Partially excerpted from Du Niang Encyclopedia.

The chemical reaction of a variety of substances to form a substance is called a chemical reaction.

Ignite. For example, hydrogen is burned in oxygen to produce water: 2H2+O2===2H2O

Water is a compound of hydrogen and oxygen.

A reaction in which two or more substances react to produce a new substance. Some of these reactions are redox reactions and some are non-redox reactions. In addition, chemical reactions generally release energy.

The alphabetic relation of the chemical reaction can be expressed as: a+b c.

Characteristics of chemical reactions] multi-change one.

Such as: iron + oxygen (ignited) ferric tetroxide.

3Fe + 2O2 == Ignition = = Fe3O4

Phenomenon: Iron burns violently in oxygen, producing a large number of sparks, releasing a large amount of heat, and a black solid is produced at the bottom of the gas collector cylinder.

Instructions:1The chemical reaction has 2 or more substances participating in the reaction, but only 1 substance is generated. To put it simply, there are many substances that come together to produce a new substance.

2.Most chemical reactions are exothermic reactions, such as many combustion reactions are chemical reactions, which are exothermic reactions.

Common types of chemical reactions in junior high school chemistry].

1. Non-metal + oxygen non-metal oxide. Non-metallic elements are combined with oxygen to form non-metallic oxides. For example, 2H2+O2= H2O

Other non-metals such as sulfur, phosphorus, carbon, etc., can react with oxygen to form non-metallic oxides.

2. Metal + oxygen metal oxide. The metal reacts with oxygen to form metal oxides.

Other metals such as aluminum, zinc, and copper can react similarly with oxygen to form metal oxides.

3. Alkaline oxide + water alkali. Metal oxides react with water to form the corresponding bases. For example, CaO+H2O= H2CO3, other metal oxides Na2O, K2O, and Bao can react with water to form corresponding bases.

4. Acidic oxide + water oxygenated acid. Non-metallic oxides react with water to form the corresponding acids. Such as CO2 +H2O= H2CO3

Other non-metallic oxides SO2 and SO3 can also form corresponding acids with water.

5.Metal + non-metal anoxicate.

6.Hydrogen + non-metallic gaseous hydride.

7.Basic oxides + acidic oxides Oxygenates.

8.Ammonia + ammonium acid.