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Question
Find the odd man out:
Options
Tinning
Anodization
Alloying
Froth floatation
Solution
Froth floatation
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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.
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Corrosion can be an advantage in some case.Explain ?
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The iron rust is formed due to........................... reaction. Different
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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 ..................................................................
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a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
Give reason for the following:
A suspension of rust is basic in nature.
Write a short note on Alloying.
Which of the following method is used to prevent the accumulation of greenish layer on brass due to corrosion?
_______ forms a green colour in the water.
When one of the metals in an alloy is mercury the alloy is called _______.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Match the columns.
| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
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| d) Coating of Zinc on iron |
Write the name.
Method used to prevent corrosion of copper.
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
Write scientific reason.
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Write scientific reason.
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Explain concept with example/explain with the help of a balanced equation.
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Give the equation for the formation of rust.
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Lime water turns milky on passing carbon dioxide gas into it.
Give an example of a chemical reaction for each of the following situations:
Sound is produced
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