Explain the different types of redox reactions with example.

Explanation

Redox reactions are classified into the following types:
(i) Combination reactions: When two or more substances combine to form a single substance, the reactions are called combination reactions.
Example: 2Mg + `O_(2) rarr` 2MgO
(ii) Decomposition reactions: Chemical reactions in which a compound splits up into two or more simpler substances are called decomposition reaction.
Example: `2KClO_(3) rarr` 2KC1 + `3O_(2)`
(iii) 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: `CuSO_(4)` + Zn `rarr ZnSO_(4)` + Cu
(/v) Disproportionation reactions: The reactions in which an element undergoes simultaneously both oxidation and reduction are called as disproportionation reactions.
Example 2HCHO+`H_(2)OrarrCH_(3)OH`+HCOOH
(v) 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))+Cu^(2+)rarrZn_((aq))^(2+)+Cu_((s))`
Here Zn - oxidation, `Cu^(2+) - reduced`