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प्रश्न
What is meant by galvanisation? Why is it done?
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उत्तर
Galvanisation is a process in which a thin layer of zinc metal is deposited on iron objects. This is done to prevent iron from rusting by protecting it from contact with air and moisture. Zinc metal, being more reactive, reacts with air to form a hard layer of zinc oxide, which prevents air from passing through it.
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संबंधित प्रश्न
Two methods by which rusting of iron can be prevented are ______ and ______.
Explain why, iron sheets are coated with zinc.
State two conditions for the rusting of iron.
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
Brass is an alloy of ______.
What is done to prevent corrosion of metals?
Write three methods of preventing rusting of iron.
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
Corrosion of silver causes a black layer of _______.
To prevent corrosion of iron and steel _______ method is used.
_______ forms a green colour in the water.
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 scientific reason.
On exposure to air, silver articles turn blackish after some time.
Explain concept with example/explain with the help of a balanced equation.
Corrosion
Write a molecular formula for rust.
The process of coating the surface of the metal with a thin layer of zinc is called ______
Give the equation for the formation of rust.
Explain the following:
Lime water turns milky on passing carbon dioxide gas into it.
Give an example of a chemical reaction for the following situation:
Sound is produced
In ______ process a layer of molten tin is deposited on metals.
