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प्रश्न
What is meant by galvanisation? Why is it done?
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उत्तर
Galvanisation is a process wherein a thin layer of zinc metal gets deposited on iron objects. This is done to prevent rusting of iron by protecting it to come in contact with air and moisture. Zinc metal, being more reactive, reacts with air to form hard layer of zinc oxide, which prevents air from passing through it.
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संबंधित प्रश्न
Which of the following methods is suitable for preventing an iron frying pan from rusting?
Give reasons:
Platinum, gold and silver are used to make jewellery.
What is anodising? Give its applications.
The chemical reaction involved in the corrosion of iron metal is that of:
(a) oxidation as well as displacement
(b) reduction as well as combination
(c) oxidation as well as combination
(d) reduction as well as displacement
Fill in the following blanks with suitable words:
............ and .............. are necessary for the rusting of iron.
What are the constituents of stainless steel?
Brass is an alloy of:
(a) Cu and Sn
(b) Cu and Pb
(c) Pb and Sn
(d) Zn and Cu
Explain how the activity series accounts for each of the following:
tendency to corrosion
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.
Write three methods of preventing rusting of iron.
Answer the following question.
List two properties of alloys.
Give reason.
An iron article should be given a coat of paint
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.
Method used to prevent corrosion of copper.
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
Write a molecular formula for rust.
Give the equation for the formation of rust.
Which among the following alloys contain mercury as one of its constituents?
In ______ process a layer of molten tin is deposited on metals.
