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प्रश्न
Why do we apply paint on iron articles?
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उत्तर १
Iron articles are painted because it prevents them from rusting. When painted, the contact of iron articles with moisture and air is cut off. Hence, rusting is prevented.
उत्तर २
Iron articles are painted to prevent them from rusting. When left unpainted, the metal surface comes into contact with atmospheric oxygen, and in the presence of moisture, it becomes iron (III) oxide. But if painted, the surface does not come into contact with moisture or air, thus preventing rust.
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संबंधित प्रश्न
Give reasons:
Platinum, gold and silver are used to make jewellery.
What special name is given to their corrosion of iron?
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.
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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
Name the metal which is a constituent of blood pigment?
What is corrosion? What are necessary conditions for corrosion?
Corrosion can be an advantage in some case.Explain ?
Give reason.
A wooden article should be polished.
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Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
The table shown below gives information about four substances: A, B, C and D.
| SUBSTANCE | MELTING POINT (K) | ELECTRICAL CONDUCTIVITY | |
| SOLID | LIQUID/ AQUEOUS | ||
| A | 295 | Good | Good |
| B | 1210 | Poor | Good |
| C | 1890 | Poor | Good |
| D | 1160 | Poor | Poor |
Identify Ionic compounds from the above given substances.
Identify the correct statement from the following:
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
