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Questions
Write two methods of preventing the rusting of iron.
State two ways to prevent the rusting of iron.
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Solution
- The rusting of iron can be prevented by painting, oiling, greasing or varnishing its surface.
- Galvanisation is another method of protecting iron from rusting by coating it with a thin layer of zinc.
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Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
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`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
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Iron is _____________________.
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| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
| c) Coating of tin on copper | |
| d) Coating of Zinc on iron |
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Sound is produced
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| 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. |
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- Name the technique used to coat the aluminium articles.
