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प्रश्न
Name any two metals which do not corrode easily.
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उत्तर
- Gold
- Platinum
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संबंधित प्रश्न
Write two methods of preventing the rusting of iron.
What type of chemical reaction is involved in the corrosion of iron?
State two conditions for the rusting of iron.
The corrosion of copper produces a ______ coating of basic copper carbonate on its surface.
With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of ______.
A metal X which is resistant to corrosion is produced by the electrolysis of its molten oxide whereas another metal Y which is also resistant to corrosion is produced by the reduction of its oxide with carbon. Metal X can be used in powder form in thermite welding whereas metal Y is used in making cathodes of ordinary dry cells.
- Name the metals X and Y.
- Which of the two metals is more reactive: X or Y?
- Name one ore or metal X. Also write its chemical formula.
- Name one ore of metal Y. Also write its chemical formula.
- Name one alloy of metal X and one alloy of metal Y.
Identify the process shown in the diagram and explain it in short
What are the adverse effects of corrosion?
Choose the correct alternative and rewrite the following:
Iron is _____________________.
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Draw a neat labelled diagram.
Electrolysis
Write a molecular formula for rust.
The process of coating the surface of the metal with a thin layer of zinc is called ______
Galvanisation is a process used to prevent the rusting of which of the following?
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.
