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प्रश्न
Why is an iron grill painted frequently?
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उत्तर
To prevent rusting of iron substances, they are painted frequently. Iron is a reactive metal that starts corroding in the presence of air (oxygen) and water (moisture). Iron reacts with oxygen in moist air, forming a brown, flaky layer of iron oxide (rust) on its surface. This is called rusting. This rust causes significant damage to iron objects by weakening them. Therefore, an iron grill is painted frequently to prevent corrosion.
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संबंधित प्रश्न
What is anodising? Give its applications.
What type of chemical reaction is involved in the corrosion of iron?
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
Name five methods of preventing rusting of iron.
Name an alloy of copper. State its chemical composition and any one use.
A common metal which is highly resistant to corrosion is ______.
What is corrosion? What are necessary conditions for corrosion?
Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
Give reason.
An iron article should be given a coat of paint
Find the odd one out and give its explanation.
What is rust?
Write a molecular formula for rust.
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
Give solutions by giving examples of corrosion?
What is rust?
Give the equation for the formation of rust.
Amalgam is an alloy of ____________.
Copper objects lose their shine and form green coating of ____________.
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.
