Question

Rusting of iron is an example of _________ reaction.

Answer 1

Hint: In order to deal with this question first we will understand the process of rusting of iron then according to it we will see the chemical process and phenomenon involved in the rusting of iron and how it affects the quality of iron.

Complete step by step answer:
Rusting is a redox reaction through which oxygen acts as the oxidizing agent and iron acts as the reduction agent. The iron atoms here lose electrons to form $\text{Fe}^{++}$ ions. The electrons flow to the edge of the water droplet, where there is plenty of dissolved oxygen. After getting oxidized from oxygen in presence of moisture or water, it gives rust ($F{e_2}{O_3}.x{H_2}O$). Which is of reddish-brown color.
Rusting of iron is a redox reaction. During the process of rusting, iron metal combines with the environmental oxygen in the presence of water. This is an oxidation reaction where oxygen acts as an oxidizing agent.
Since oxygen molecules in the process also combine henceforth with the iron, this is a reduction reaction, where iron acts as a reducing agent. Reaction involve in the process are as follows:
Oxidation of iron
$2Fe \to 2F{e^{2 + }} + 4{e^ - }$

Reduction of oxygen
${O_2} + 2{H_2}O + 4{e^ - } \to 4O{H^ - }$

The rusting process decreases the quality of the iron.
Hence, rusting of iron is an example of redox reaction.

Note: Rust is formed in the presence of moisture, when an iron surface is exposed to oxygen. Rust is non-toxic, and thus does not pose biological hazards. The key environmental effects of rust are the corrosion of steel and iron buildings, such as bridges, vehicles, etc. Few ways we can avoid rusting are: lighting, cathodic safety, and galvanization.