Question

Write two methods of preventing the rusting of iron.

Answer 1

Hint: Rusting of iron refers to the formation of a reddish layer on iron metal due to the moisture in surroundings. It can be prevented when the metal does not directly come in contact with the moisture in the surroundings.

Complete answer:
Rusting basically refers to a reddish layer that develops over time on iron metal and also weakens it and makes it fragile.
It is the loss of iron in the form of iron oxide when iron comes in contact with surroundings consisting of air and moisture resulting in redox reaction.
The rusting of iron is also the most familiar example of corrosion.
Corrosion is defined as the loss of metal in the form of its oxide during the course of its interaction with the environment and is due to the electrochemical process.
We can prevent corrosion by not letting the air and moisture come in contact with the iron metal directly which can be achieved in the following ways:
i) Coating the surface: The surface of iron can be coated with oil, grease, paint, etc. so that the air and moisture does not directly come in contact with iron preventing its oxidation.
ii) Galvanization: It refers to the process of applying a zinc layer on the iron to prevent corrosion and it can be done with the help of electrolysis.
iii) Alloying: Iron reacts with metal to gain a chemically stable state so we can mix it with more stable elements and slow down the process of rusting.

Note: The chemical reaction for rusting of iron so as to observe its oxidation can be given as:
Iron + Oxygen + water (moisture) $\to$ Iron (II) oxide and Iron (III) oxide
$4Fe + 2{O_2} + x.{H_2}O\to 2F{e_2}{O_3}.X{H_2}O$
Chemically rust is Iron (III) oxide.