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प्रश्न
Explain why, iron sheets are coated with zinc.
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उत्तर
Iron sheets are coated with zinc because zinc is a reactive metal which readily reacts with oxygen present in air to form a hard layer of zinc oxide. This layer is so hard that it prevents air and moisture from passing through it. Hence, moist air cannot come in contact with iron. This in turn prevents the rusting of iron.
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संबंधित प्रश्न
Which metals do not corrode easily?
What type of chemical reaction is involved in the corrosion of iron?
What are the constituents of stainless steel?
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
Name a common metal which is highly resistant to corrosion.
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.
Name the metal which is a constituent of plant pigment?
Give reason.
An iron article should be given a coat of paint
Give a reason why rust turns moist red litmus blue.
Find the odd one out and give its explanation.
Write the name.
Method used to prevent corrosion of copper.
Complete flow chart given below.
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
Galvanisation is a process used to prevent the rusting of which of the following?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
Explain the chemical reactions in rusting of iron.
