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प्रश्न
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
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उत्तर
- The process of coating metals such as aluminium and copper with a thin and strong layer of their oxides by electrolysis is called anodizing process.
- When aluminium is anodized, a thin layer of aluminium oxide is formed all over the surface. This restricts the contact of aluminium metal with oxygen and water and prevents corrosion of aluminium.
Hence, anodization method is useful for prevention of the corrosion of the aluminium.
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संबंधित प्रश्न
What is an alloy?
Why do we apply paint on iron articles?
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
The corrosion of iron is called ______.
Tiffin boxes are electroplated with ______ but car bumpers are electroplated with ______ to protect them from rusting.
The corrosion of copper produces a ______ coating of basic copper carbonate on its surface.
What are the special properties of stainless steel?
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
Name a common metal which is highly resistant to corrosion.
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.
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- 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.
Mention two uses of the following metals and non-metals
Iron
What is corrosion? What are necessary conditions for corrosion?
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
Write three methods of preventing rusting of iron.
Give reason.
Copper and brass utensils should be tinned.
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.
Give a reason why rust turns moist red litmus blue.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
Observe the following picture and answer the following questions:
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- Write the chemical formula of rust.
- Write the reaction of oxidation of iron at the anode.
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To prevent corrosion of iron and steel _______ method is used.
When one of the metals in an alloy is mercury the alloy is called _______.
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Rusting of iron : Fe2O3 : : corrosion of copper : ______
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Write the name.
Method used to prevent corrosion of copper.
Observe the following diagram and write answers.
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- Explain the method.
- Give two examples of this method.
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Give the equation for the formation of rust.
Amalgam is an alloy of ____________.
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Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?
A man painted his main gate made up of iron, to
- prevent it from rusting.
- protect it from sun.
- make it look beautiful.
- make it dust free.
Which of the above statement(s) is/are correct?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
| 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.
