Redox Reactions And Its Types - Decomposition, Displacement

What is a RedOx Reaction?

A Reduction reaction is defined as the gain of electrons while the loss of electrons is referred to as oxidation. In other words, oxidation is loss whereas reduction is a gain. Reduction and oxidation reactions occur simultaneously and hence they are together known as Redox Reactions. These reactions can be further classified into different types.

Types of redox reactions:

  • Decomposition Reaction:

    This kind of reaction involves the breakdown of a compound into different compounds. Examples of these types of reactions are:
    \( 2NaH \rightarrow 2Na + H_2\)
    \( 2H_2O \rightarrow 2H_2 + O_2\)
    \(Na_2CO_3 \rightarrow Na_2O + CO_2\)
    All the above reactions results in breakdown of smaller chemical compounds in the form of \(AB \rightarrow A + B\)

    But, there is a special case that confirms that all the decomposition reactions are not redox reactions.
    For example: \(CaCO_3 \rightarrow CaO + CO_2\)

  • Combination Reaction:

    These reactions are the opposite of decomposition reaction and hence involve the combination of two compounds to form a single compound in the form of \( A+B \rightarrow AB\)

    Examples of these types of reactions are:

    \( H_2 + Cl_2 \rightarrow 2HCl\)

    \( C + O_2 \rightarrow CO_2\)

    \( 4Fe + 3O_2 \rightarrow 2Fe_2O_3\)

  • Displacement Reaction:

    In this kind of reaction, an atom or an ion in a compound is replaced by an atom or an ion of another element. It can be represented in the form of \( X + YZ \rightarrow XZ + Y \).
    Further displacement reaction can be categorized into metal displacement and non-metal displacement.
  • Metal displacement:

    In this type of reaction, a metal present in the compound is displaced by another metal. These types of reactions find their application in metallurgical processes where pure metals are obtained from their ores.

    Example of this kind of reaction:

    \( CuSO_4 + Zn \rightarrow Cu + ZnSO_4 \)

  • Non-metal displacement:

    In this type of reaction, we can find a hydrogen displacement and sometimes rarely occurring reactions involving oxygen displacement.

The importance of redox reactions in today’s world cannot be denied. They are being used in several industries.

Click on this link for NCERT Solutions for redox reactions.

Practise This Question

Which of the following is an example for intra-molecular redox reaction?