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प्रश्न
What is done to prevent corrosion of metals?
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उत्तर
Corrosion of metals can be prevented by the following methods:
- Applying coatings: Metals are coated with oil, grease, varnish, or paint to prevent direct contact with air and moisture.
- Metal plating: Metals are plated with a non-corroding metal. For example, zinc plating (galvanization) is used to protect iron from rusting.
संबंधित प्रश्न
Two methods by which rusting of iron can be prevented are ______ and ______.
Name a common metal which is highly resistant to corrosion.
A common metal which is highly resistant to corrosion is:
(a) iron
(b) copper
(c) aluminium
(d) magnesium
Corrosion can be an advantage in some case.Explain ?
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
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.
Answer the following question.
List two properties of alloys.
Write scientific reason.
On exposure to air, silver articles turn blackish after some time.
Write scientific reason.
Coins are made from metals and alloys.
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
