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प्रश्न
What is rust?
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उत्तर
When iron is exposed to moist air, it forms a layer of brown hydrated ferric oxide on its surface. This compound is known as rust and the phenomenon of formation of rust is known as rusting.
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संबंधित प्रश्न
What are alloys?
Explain why Iron sheets are coated with zinc during galvanization.
What type of chemical reaction is involved in the corrosion of iron?
What is meant by galvanisation? Why is it done?
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
Observe the following picture a write down the chemical reaction with the explanation.
What is done to prevent corrosion of metals?
Give reason for the following:
A suspension of rust is basic in nature.
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
| A process of forming a thick oxide of aluminium when aluminium is exposed to air. This coat makes it resistant to corrosion. Resistance can be improved by making a layer of oxide thinker. In this technique, the aluminium article is the anode, and the electrolyte is sulphuric acid. The anode reaction results in the formation of a black-coloured film of aluminium oxide on the anode. By putting appropriate dyes in the electrolytic solution, both coloured surface with the decorative finish is achieved. Kitchen articles like anodised such as pressure cookers, pans and frames of sliding windows are applications of this technique. |
- Name the anode and electrolyte used in this technique.
- How can we make aluminium articles made resistant to corrosion?
- Name the technique used to coat the aluminium articles.
