Question

What special name is given to corrosion of iron?

Answer 1

We need to know that the corrosion is when a refined metal is naturally converted to a more stable form such as its oxide, hydroxide or sulphide state this leads to deterioration of the material. Rusting of iron refers to the formation of rust, a mixture of iron oxides, on the surface of iron objects or structures.

Complete answer:
We need to know that when a metal is attacked by substances around it, such as moisture, acids, etc, it is said to corrode and this process is called corrosion. Corrosion of iron is called rusting. We can understand this process briefly: The rust is formed from a redox reaction between oxygen and iron in an environment containing water. The rusting of iron is characterized by the formation of a layer of a red, flaky substance that easily crumbles into a powder.
The reaction taking place in the formation of rust is given below:
Oxygen is a highly active oxidizing agent whereas iron is a reducing agent. Therefore, the iron atom immediately gives up electrons when exposed to oxygen.
The chemical reaction takes place as follows
$Fe \to F{e^{2 + }} + 2{e^-}$
The oxidation state of iron is further increased by the oxygen atom when water is present in the atmosphere
$4F{e^{2 + }} + {O_2} \to 4F{e^{3 + }} + 2{O^{2 - }}$
The listed below acid-base reactions occur between the iron cations and the water molecules.
$F{e^{2 + }} + 2{H_2}O \rightleftarrows Fe{\left( {OH} \right)_2} + 2{H^ + }$
$F{e^{3 + }} + 3{H_2}O \rightleftarrows Fe{\left( {OH} \right)_3} + 3{H^ + }$
The hydroxides of iron are also formed from the direct interaction and reaction between the iron cations and hydroxide ions.
${O_2} + {H_2}O + 4{e^-} \to 4O{H^-}$
$F{e^{2 + }} + 2O{H^ - } \to Fe{\left( {OH} \right)_2}$
$F{e^{3 + }} + 3O{H^-} \to Fe{\left( {OH} \right)_3}$

Note:
We need to know that the rust is the result of corroding steel after the iron ($Fe$) particles have been exposed to oxygen and moisture (e.g., humidity, vapor, immersion). Oxygen causes these electrons to rise up and form hydroxyl ions ($OH$).