Question

Why is there a necessity of galvanisation of iron articles ?

Answer 1

Hint: Around us we find so many things made up of iron. The iron from these items can oxidise and rust will be formed and spoil the things. So the protective layer is made as coating on iron and steel articles to prevent them from rusting. This process of application of protective coating is called Galvanisation.

Complete step by step answer:
As we all are aware of the extensive use of Iron and objects made from it, practically everywhere around us, like house construction, vessels, bridges, iron chains, etc.
So thus this iron and steel objects come into contact with oxygen, moisture and water vapour and thus causes rusting reducing the life of such articles. This can lead to great loss of property and money and sometimes even life.
Hence protection of iron and steel becomes an essential factor to prevent above mentioned loss. One famous method of prevention of iron and steel articles is galvanisation.
A process in which the protective layer of zinc is applied as coating to prevent from rusting such a process is called galvanisation. The metals like zinc and magnesium are used to make protective coating, and these metals are called sacrificial metals. As these metals undergo oxidation, by preventing iron to form rust.
Thus, we conclude that galvanizing is essential and necessary for iron articles.

Additional Information: After galvanising, the protective layer is formed, but after sometimes, at some places, the layer gets scratched or removed, but still the other parts of layer will not allow attack of oxygen on that scratched area, rather first the remaining coated area gets attacked and prevents the scratched or exposed iron area from rusting.

Note: As we know that in electrochemical series, the elements which are more reactive are placed at top and less reactive are placed at bottom. So the elements like zinc and magnesium are above iron, thus they can be used for galvanizing. As they will react with oxygen and moisture in air, and prevent iron from reacting and rusting. Thus, Galvanising is a better way of protecting iron from rusting.