Advertisements
Advertisements
प्रश्न
Why do we apply paint on iron articles?
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Two methods by which rusting of iron can be prevented are ______ and ______.
Fill in the following blank with suitable word:
The corrosion of iron is called ................
Name five methods of preventing rusting of iron.
What are the constituents of stainless steel?
Name the metal which is a constituent of plant pigment?
State under what conditions corrosion is faster ?
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.
What is done to prevent corrosion of metals?
Answer the following question:
What is corrosion? Do gold ornaments corrode? Justify.
Write three methods of preventing rusting of iron.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
Pressure cooker : Anodizing : : Silver plated spoons : _______
What is rust?
Write a molecular formula for rust.
State two conditions necessary for rusting of iron.
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.
Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
