What is Redox Reaction? What is Redox Reaction?

Simple understanding: the reaction of a substance with oxygen to form an oxide is called an oxidation reaction.

The reaction of a compound with oxygen is not necessarily an oxidation reaction, for example, if the resulting compound contains oxygen but is not an oxide, it is not called an oxidation reaction.

Complication: Redox reaction is a chemical reaction in which the oxidation number of an element changes before and after the reaction. This reaction can be understood as consisting of two halves, namely oxidation and reduction.

Concept The essence of the reaction is that there is a change in the oxidation number, that is, there is a transfer of electrons. The half-reaction in which the oxidation number increases, i.e., the electrons are lost, is an oxidation reaction; The oxidation number decreases, and the reaction to obtain electrons is a reduction reaction. The substances with an increased oxidation number reduce each other and are oxidized by themselves, so they are called reducing agents, and their products are called oxidation products; The substance with a reduced oxidation number oxidizes the other party and is reduced by itself, so it is called an oxidant, and its product is called a reduction product.

It is a reaction in which the valency of the element changes, that is, the electron transfer occurs, which is the redox reaction.

The action of a substance losing electrons is called an oxidation reaction; The action of gaining electrons is called the reduction reaction.

Definition of redox reaction: A class of reactions in which the oxidation number of an element changes before and after a chemical reaction is called a redox reaction.

Before and after the redox reaction, the oxidation number of the element changes. Depending on the increase or decrease in the oxidation number, the redox reaction can be split into two half reactions: the half reaction with the increased oxidation number is called the oxidation reaction; The reaction with a decrease in oxidation number is called a reduction reaction.

Oxidation and reduction reactions are interdependent and cannot exist independently, and together they constitute redox reactions.

In the reaction, the substances that undergo oxidation reactions, called reducing agents, produce oxidation products; A substance that undergoes a reduction reaction, called an oxidant, produces a reduction product. Oxidation products are oxidizing but weaker than oxidants; The reducing product is reducing, but weaker than the reducing agent.

Oxidation-reduction reaction is a type of reaction in which the oxidation number of an element changes before and after a chemical reaction.

The essence of a redox reaction is the gain or loss of electrons or the shift of shared electron pairs. The redox reaction is one of the three basic reactions in chemical reactions (the other two are the (Lewis) acid-base reaction and the free radical reaction).

Combustion, respiration, photosynthesis, chemical batteries in production and life, metal smelting, rocket launches, etc. are all closely related to redox reactions in nature. The study of redox reactions is of great significance to the progress of mankind.

Strength and weakness law: oxidation: oxidant oxidation product; Reducibility: Reducing agent" reducing product.

Valence law: the element is in the most advanced state and only has oxidation; The element is in the lowest valence state and is only reductive; It is in the intermediate valence state, which is both oxidizing and reducing.

Transformation law: when the centering reaction occurs between different valence states of the same element, the oxidation number of the element is only close but not crossed, and the maximum value of the element reaches the same valence state.

Priority law: For the same oxidant, when there are multiple reducing agents, it usually reacts with the most reducing agent first.

Conservation law: The number of electrons gained by the oxidizing agent is equal to the number of electrons lost by the reducing agent.

The above content refers to: Encyclopedia - Redox Reaction.

A redox reaction is a chemical reaction in which the valency of an element before and after the reaction has a corresponding rise and fall change. The chemical reaction with the valency change of the elements in the reaction process is called redox reaction. Such reactions are subject to conservation of charge!

Because electron transfer occurs in the redox reaction, that is, the valency of the element changes, it can be known:

Metathesis reaction is not a redox reaction.

The displacement reaction must be a redox reaction, and the synthesis and decomposition reaction is not necessarily a redox reaction.

A chemical reaction with the participation of elemental elements must be a redox reaction.

The decomposition reaction with the formation of elemental matter must be a redox reaction, but the reaction with the participation of elemental matter is not necessarily a redox reaction (such as graphite turning into diamond, oxygen turning into ozone).The metathesis reaction must not be a redox reaction.

For chemical reactions that do not belong to the four basic types of reactions mentioned above, there are redox reactions (e.g., carbon monoxide to copper oxide) and those that do not belong to redox reactions (e.g., oxygen reacts to become ozone under certain conditions).

The centering reaction, the disproportionation reaction can be regarded as a special redox reaction.

What is redox reaction is as follows:

A chemical reaction in which the valency of an element rises and falls during the reaction is a redox reaction.

The essence of a redox reaction is the gain and loss of electrons or the shift of shared electron pairs in the reaction process. It is characterized by the rise and fall of the valence.

Basic concepts about redox reactions

1. Oxidizing agent and reducing agent

An oxidizer is a substance that gets electrons (or electron pair bias, reduced valency). A reducing agent is a substance that loses electrons (or deviates from electron pairs, increases valency). Oxidizing agents are oxidizing and reducing agents are reducing.

2. Oxidation reaction and reduction reaction

Oxidation is a reaction in which electrons are lost (valency increases). The reduction reaction is the anti-valence response to get electrons (reduced valency).

3. Oxidation products and reduction products

The oxidation product is the product formed by the oxidation of the reducing agent after losing electrons in the reaction. Reduction products are the products formed by the reduction of oxidants after gaining electrons in the reaction.

4. Oxidation and reduction

The electron-gaining property of the oxidizing agent is called oxidation, and the electron-losing property of the reducing agent is called reductiveness.

The mantra of redox reaction is to increase (increase in valency) lose (lose electrons) oxygen (be oxidized, oxidation reaction occurs) and return (do reducing agent, itself has reducibility), decrease (reduce valency) gain (gain electrons) and return (be reduced, reduce reaction) oxygen (to be oxidant, Shenzhen itself has oxidation).

Oxidation reactions were the earliest reactions in which metals or non-metals combine with oxygen to form oxides, and the valency of another element in such reactions always increases. The earliest reduction reactions were reactions in which metals were refined from their compounds, in which the valency of the metals always decreased.

For example, in the reaction of industrial ironmaking, ferric oxide is the oxidizing agent, and carbon monoxide is the familiar reducing agent. The oxygen element in ferric oxide gives carbon monoxide, which increases the oxygen content of the latter. Addition becomes carbon dioxide.

Iron changes from 3-valent to elemental 0-valent (reduced, oxidizing agent), while carbon changes from 2-valent to 4-valent (elevated, reducing agent).