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प्रश्न
Complete flow chart given below.
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उत्तर
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संबंधित प्रश्न
What is an alloy?
Explain the term corrosion.
Explain why Iron sheets are coated with zinc during galvanization.
What is anodising? Give its applications.
What type of chemical reaction is involved in the corrosion of iron?
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
Name the metal which is used for galvanising iron.
In one method of rust prevention, the iron is not coated with anything. Which is this method?
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What is the corrosion of iron known as?
With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
Name five methods of preventing rusting of iron.
What are the constituents of stainless steel?
Name a common metal which is highly resistant to corrosion.
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of ______.
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.
- Name the metals X and Y.
- 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.
Bronze is an alloy of ______.
Name the metal which is a constituent of blood pigment?
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.
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.
Find the odd man out:
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
What is ‘rusting’?
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
Corrosion of silver causes a black layer of _______.
Stainless steel is an alloy of _______.
Rusting of iron : Fe2O3 : : corrosion of copper : ______
Bronze : _______ : : Stainless steel : Fe + Cr + C
Find the odd one out and give its explanation.
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
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?
Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
Which among the following alloys contain mercury as one of its constituents?
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?
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
