Question

Bridges made up of iron are coated with a layer of zinc, this is because

• A. Zinc is better conductor of heat.
• B. Zinc is more durable than iron
• C. Zinc is less reactive than iron
• D. Zinc prevents corrosion

Answer 1

The correct option is D

Zinc prevents corrosion

Zinc is more reactive than iron. But after reaction with oxygen, water molecules and carbon dioxide in air it forms dull grey layer of zinc carbonate which prevents further corrosion.