Question

Explain the different types of redox reactions with example.

Answer 1

Redox reactions are classified into the following types:

(1) Combination reactions: When two or more substances combine to form a single substance, the reactions are called combination reactions. 

Example: 2Mg + O₂ → 2MgO

(2) Decomposition reactions: Chemical reactions in which a compound splits up into two or more simpler substances are called decomposition reaction. 

Example: 2KClO₃ → 2KCl + 3O₂

(3) Displacement reactions: The reactions in which one ion or atom in a compound is replaced by an ion or atom of the other element are called displacement reactions.

Example: CuSO₄ + Zn → ZnSO₄ + Cu

(4) Disproportionation reactions: The reactions in which an element undergoes simultaneously both oxidation and reduction are called as disproportionation reactions. 

Example: 2HCHO + H₂O → CH₃OH + HCOOH

(5) Competitive Electron transfer reactions: These are the reactions in which redox reactions take place in different vessels and it is an indirect redox reaction. There is a competition for the release of electrons among different metals. 

Example: Zn_(s) + Cu²⁺ → Zn²⁺_(aq) + Cu_(s)  

Here Zn – oxidised; Cu²⁺ reduced