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प्रश्न
Name two metals which resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface.
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उत्तर
Aluminium and zinc are two metals that resist corrosion due to the formation of a thin, hard and impervious layer of oxide on their surface. Aluminium and zinc form tough layers of aluminium oxide and zinc oxide by reacting with air.
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संबंधित प्रश्न
Tinning : Tin : : Galvanizing : _________
Explain the terms Corrosion
Which metals do not corrode easily?
Write a chemical equation to show the process of corrosion of iron.
In one method of rust prevention, the iron is not coated with anything. Which is this method?
Explain why, through aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
What are the special properties of stainless steel?
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) hydrated copper sulphate
(b) copper oxide
(c) basic copper carbonate
(d) copper nitrate
No chemical reaction takes place when granules of a rusty-brown 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.
(a) What could the solids A and B be?
(b) What are the products C and D most likely to be?
(c) Write the chemical equation for the reaction between A and B leading to the formation of C and D. Mention the physical states of all the reactants and products in this equation and indicate the heat change which takes place.
(d) What is the special name of such a reaction? State one use of such a reaction.
(e) Name any two types of chemical reactions under which the above reaction can be classified.
Bronze is an alloy of ______.
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
Give reason for the following:
A suspension of rust is basic in nature.
To prevent corrosion of iron and steel _______ method is used.
Draw a neat labelled diagram.
Anodizing
Write a molecular formula for rust.
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
Give the equation for the formation of rust.
Which among the following alloys contain mercury as one of its constituents?
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
