Coating of Iron with Zn is:

Question

Accepted Answer

The correct option is (3):

Galvanization is the process of applying a protective zinc coating to iron or steel to prevent rusting. This is typically done by hot-dip galvanizing, where the iron is submerged in a bath of molten zinc. The zinc coating serves two primary protective functions. Firstly, it acts as a physical barrier, preventing oxygen and water (which cause rust) from reaching the iron surface. Secondly, even if the zinc coating is scratched and the iron is exposed, the zinc provides "sacrificial protection" because zinc is more reactive than iron. This means the zinc will corrode preferentially, protecting the underlying iron from rust. This electrochemical protection significantly extends the lifespan of iron and steel products, making them more durable in various environments.

The incorrect option is (1): Smelling.
"Smelling" refers to the act of detecting odors with the nose or emitting an odor. It has no chemical or physical relation to the process of coating iron with zinc for protection.

The incorrect option is (2): Rusting.
Rusting is the common term for the corrosion of iron and its alloys, such as steel. It is an oxidation reaction where iron reacts with oxygen and water to form iron oxides (rust), which is precisely what galvanization aims to prevent. Therefore, coating iron with zinc is a method to *prevent* rusting, not the process of rusting itself.

The incorrect option is (4): All of the above.
Since "Smelling" and "Rusting" are incorrect descriptions of the process of coating iron with zinc, "All of the above" cannot be the correct answer. Only galvanization accurately describes this protective coating method.