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प्रश्न
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
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उत्तर
The galvanised iron-zinc oxide layer coating on iron objects prevents zinc and iron under it from corrosion. This happens because zinc is more reactive than iron. If the zinc layer is broken, zinc, being more reactive, gets oxidised before iron and prevents its corrosion.
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संबंधित प्रश्न
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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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