Question

Tick the most appropriate answer.

Galvanising is the process of coating iron with a layer of molten:

• A. zinc
• B. tin
• C. copper
• D. silver

Answer 1

The correct option is A

zinc

Part 1: Rusting: The slow conversion of iron into its hydrated ferric oxide, in the presence of moisture and air, is called rusting, and the hydrated oxide of iron is called rust. The given reaction is:

• $\underset{\mathrm{Iron}}{4\mathrm{Fe}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{3{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Ferric}\mathrm{oxide}}{2{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}$
• $\underset{\mathrm{Ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Water}}{{\mathrm{xH}}_2\mathrm{O}}\left(\mathrm{l}\right)\to \underset{\mathrm{Hydrated}\mathrm{ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O}\left(\mathrm{s}\right)}\left(\mathrm{rust}\right)$

Part 2: Galvanization

• The process of adding a protective zinc coating to steel or iron to prevent rusting is known as galvanization or galvanizing.
• The zinc coating is applied using the hot-dip electroplating process. Zinc prevents the formation of an oxide layer on iron, which leads to rust in the presence of air and water.
• The most prevalent method is hot-dip galvanizing, which involves immersing items in molten zinc baths.

So, the correct option is (A)