While playing in your building compound, you might have come across an iron barbed wire which has turned red. You might have also seen some old metallic object at home. You would realise that these objects have turned reddish, unlike their original metallic colour. This is what we call rusting of iron.
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Consequences in daily life
Rusting happens on the surface of iron objects making it coarse and flaky. It also makes the iron objects fragile. Rusting happens quicker in a humid environment. As a result, it is easier for water tanks and pipes to get rusted. Therefore, various methods are used to reduce the effect of rusting. Getting wounded from a corroded metal object especially rusted iron objects can prove to be dangerous.
Chemistry of Rusting of Iron
- Scientific Name of Oxide of Iron (II) is Ferrous Oxide (FeO).
- Scientific Name of Oxide of Iron (III) is Ferric Oxide (Fe2O3).
Prevention from Rusting
Methods used to prevent Rusting of Iron are as follows:
- Alloying – Since Rusting of Iron is a chemical process that happens because the metal is attaining more stable chemical state, alloying (mixing) the iron with other stable metals or alloys can slow down the process of rusting.
- Galvanizing – Galvanizing a metal object means to coat the surface of that object with a layer of metallic zinc. Also, it is an inexpensive procedure. In conclusion, it will provide it with protection against rusting.
- Coating and Painting – Coating the surface of a metal object with a layer of either Paint or Varnish will break the contact between the surface and atmospheric oxygen making it consequently immune to rusting.
- Humidity Control – Controlling the humidity of the environment is also a solution. Therefore, the chances of the metal object rusting will reduce.
Solved Examples for You
Question: In which test tubes, the rusting of the iron nail will take place?
- a and d
- a, b and d
- b and c
- b, c and d
Solution: B. Rusting of iron takes place only in presence of oxygen and water vapour. In figure (c) rusting is not possible as the supply of oxygen is blocked by oil layer.
Question: Rusting is a special term, given to the corrosion of which metal?
Solution: D. Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide, hydroxide, or sulfide. Rust is a general term for a series of iron oxides, usually, red oxides, formed by the reaction of iron with oxygen in the presence of water or air moisture. Rusting is the common term for corrosion of iron and its alloys, such as steel. Many other metals undergo similar corrosion, but the resulting oxides are not commonly called rust. Rusting is a special term for corrosion of the metal Iron.