Question

Explain how a painting of an iron gate prevents it from rusting?

Answer 1

Hint: Rusting is the process in which the formation of hydrated iron oxide takes place when the iron comes in contact with the oxygen and water. In the atmosphere, about 21% of oxygen is present which can react with iron easily.

Complete answer:
- In the given question, we have to explain the reason behind how the painting of an iron gate prevents it from rusting.
- As we know that rusting is the formation of the iron oxide in the hydrated form. It is a natural process.
- Because any substance which is made up of iron metal when kept open for a long time then it reacts with the atmospheric oxygen and moisture present in the environment.
- As we can see the balanced chemical reaction given below:
 \[\text{4Fe + 3}{{\text{O}}_{2}}\text{ + 3}{{\text{H}}_{2}}\text{O }\to \text{ 3F}{{\text{e}}_{2}}{{\text{O}}_{3}}\text{ }\cdot \text{ 3}{{\text{H}}_{2}}\text{O}\].
- So, if we paint the iron gate then the contact between the iron and oxygen and water will not take place.
- Due to which they will not react and no rusting will take place.
- Paints which are oil-based are considered mostly as long as the paint is present on the iron surface it prevents the rusting from taking place.
- That's why paint is applied to the iron gates as prevention from rusting.

Note:
Along with the painting method, other methods are also present to prevent the rusting such as galvanisation in which the coating of another metal like zinc(which can be oxidised faster than the iron) is done as a protective layer, etc.