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प्रश्न
Give the constituents and one use of brass.
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उत्तर
Brass is an alloy of copper and zinc. Composition of brass is copper (80 percent) and zinc (20 percent). Brass is used for making vessels and scientific instruments (e.g.microscope).
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संबंधित प्रश्न
Which of the following methods is suitable for preventing an iron frying pan from rusting?
What special name is given to the corrosion of iron?
In one method of rust prevention, the iron is not coated with anything. Which is this method?
Fill in the following blank with suitable word:
The corrosion of iron is called ................
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?
A common metal which is highly resistant to corrosion is:
(a) iron
(b) copper
(c) aluminium
(d) magnesium
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.
(a) Name the metals X and Y.
(b) Which of the two metals is more reactive : X or Y?
(c) Name one ore or metal X. Also write its chemical formula.
(d) Name one ore or metal Y. Also write its chemical formula.
(e) Name one alloy of metal X and one alloy of metal Y.
Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
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 ..................................................................
Answer the following question.
List two properties of alloys.
_______ is an alloy made from iron, carbon and chromium.
To prevent corrosion of iron and steel _______ method is used.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Explain concept with example/explain with the help of a balanced equation.
Corrosion
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Explain the chemical reactions in rusting of iron.
