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प्रश्न
Name an alloy of copper. State its chemical composition and any one use.
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उत्तर
An alloy of copper is bronze. The constituent elements of bronze are copper and tin.
The composition of bronze is 90 percent copper and 10 percent tin. This alloy of copper is very strong and prevents corrosion.
Bronze is used in the manufacturing of statues, medals, cooking vessels etc.
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संबंधित प्रश्न
What special name is given to the corrosion of iron?
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
Fill in the following blanks with suitable words:
............ and .............. are necessary for the rusting of iron.
Name five methods of preventing rusting of iron.
What are the special properties of stainless steel?
In stainless steel alloy, iron metal is mixed with:
(a) Cu and Cr
(b) Cr and Ni
(c) Cr and Sn
(d) Cu and Ni
Explain how the activity series accounts for each of the following:
tendency to 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 ..................................................................
Identify the process shown in the diagram and explain it in short
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
Write the name.
An alloy of copper and tin-
Write the name.
Method used to prevent corrosion of copper.
Draw a neat labelled diagram.
Anodizing
Complete flow chart given below.
Write a molecular formula for rust.
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
Observe the following figure and write the answer of the question.
- Which process is shown in the figure?
- Explain the chemical reaction shown in the figure.
- Write the reactions on anode and cathode.
Give preventive methods by giving examples of corrosion?
Gold plated ornaments is the example of ______.
| 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.
