Rusting of iron is an example of ________

Options

A. Addition reaction
B. Displacement reaction
C. Dissociation reaction
D. Redox Reaction

Answer

D

Explanation

The reaction in which oxidation and reduction occurs simultaneously is called Redox reaction. Rust of iron is nothing but hydrate of iron oxide `(Fe_2O_3.nH_2O)` and iron(III) oxide -hydroxide `(FeO(OH)Fe(OH)_3)`. It is an electrochemical process, half reactions of which are as follows.
1. `O_2 + 4e^(-) + 2 H_2O to 4 OH^(-)`
Here oxygen gains electrons thus, it is oxidizing agent.
2.`Fe to Fe^(2+) + 2e^(-)` as you can see from this half cell reaction Fe by loses electron and thus it is reducing agent.
Thus in rusting of iron reduction and oxidation occurs indeed, and hence it is a Redox reaction.