Question

Galvanization is done to prevent

• A. Rusting
• B. Burning
• C. Freezing
• D. Melting

Hint:

Remember: Galvanization = coating iron with Zinc to prevent Rust. The key principle is sacrificial protection --- zinc is more reactive than iron in the electrochemical series, so zinc corrodes preferentially, protecting the iron beneath. Other corrosion-prevention methods include painting, oiling, tinning (coating with tin), and alloying (stainless steel).

Answer 1

The Correct Option is A

Concept:

Galvanization (also spelled galvanisation) is a process of applying a protective zinc coating to iron or steel to prevent rusting (corrosion). The zinc layer acts as a sacrificial barrier protecting the underlying iron from reacting with oxygen and moisture in the environment.

Step 1: What is rusting?
Rusting is the process by which iron (Fe) reacts with oxygen (O2) and water (H2O) to form hydrated iron(III) oxide, commonly known as rust:
Rust weakens and degrades iron structures, making rust prevention critically important.

Step 2: How does galvanization work?
In galvanization:

• A thin layer of

zinc (Zn) is coated on the iron or steel surface.

• Zinc acts as a

physical barrier --- it separates iron from oxygen and moisture.

• More importantly, zinc acts as a

sacrificial anode: since zinc is more reactive than iron (higher position in the electrochemical/activity series), zinc preferentially oxidizes instead of iron. Even if the zinc layer is scratched, it continues to protect the exposed iron around it.

• The protective reaction: Zinc oxidizes to form a thin layer of zinc carbonate (ZnCO3) which is adherent and further protects the surface.

Step 3: Galvanization has no connection with burning, freezing, or melting.

• Burning is a rapid chemical reaction (combustion) with oxygen releasing heat and light. Galvanization offers no protection against combustion.

• Freezing is a physical change (liquid to solid). Zinc coating does not affect the freezing point of iron.

• Melting is a physical change (solid to liquid). The thin zinc coating does not affect the melting point of iron significantly.

Step 4: Common applications of galvanized iron/steel.
Galvanization is used in: roofing sheets (corrugated iron roofs), buckets and containers, fences, nuts and bolts, automotive parts, and construction beams exposed to weather.