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प्रश्न
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
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उत्तर
- The process of coating metals such as aluminium and copper with a thin and strong layer of their oxides by electrolysis is called anodizing process.
- When aluminium is anodized, a thin layer of aluminium oxide is formed all over the surface. This restricts the contact of aluminium metal with oxygen and water and prevents corrosion of aluminium.
Hence, anodization method is useful for prevention of the corrosion of the aluminium.
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संबंधित प्रश्न
Give two examples of alloys with their chemical composition.
What are alloys?
Explain the term “corrosion” with an example. Write a chemical equation to show the process of corrosion of iron.
Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.
Explain why, iron sheets are coated with zinc.
The corrosion of copper produces a ______ coating of basic copper carbonate on its surface.
______ and ______ are necessary for the rusting of iron.
With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Give the constituents of brass.
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
What are the constituents of stainless steel?
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.
Four metals P, Q, R and S are all obtained by the reduction of their oxides with carbon. Metal P is used to form a thin layer over the sheets of metal S to prevent its corrosion. Metal Q is used for electroplating tiffin boxes made of metal S whereas metal R is used in making car batteries. Metals Q and R form an alloy called solder. What are metals P, Q, R and S? How have you arrived at this conclusion?
Corrosion can be an advantage in some case.Explain ?
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
Identify the process shown in the diagram and explain it in short
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
What is ‘rusting’?
Give reason for the following:
A suspension of rust is basic in nature.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
_______ is an alloy made from iron, carbon and chromium.
When one of the metals in an alloy is mercury the alloy is called _______.
Find the odd one out and give its explanation.
Match the columns.
| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
| c) Coating of tin on copper | |
| d) Coating of Zinc on iron |
Write the name.
An alloy of copper and tin-
Draw a neat labelled diagram.
Electrolysis
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.
The process of coating the surface of the metal with a thin layer of zinc is called ______
Copper objects lose their shine and form green coating of ____________.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
A man painted his main gate made up of iron, to
- prevent it from rusting.
- protect it from sun.
- make it look beautiful.
- make it dust free.
Which of the above statement(s) is/are correct?
Give an example of a chemical reaction for the following situation:
Sound is produced
Gold plated ornaments is the example of ______.
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
