Advertisements
Advertisements
प्रश्न
Explain the term corrosion.
Advertisements
उत्तर
Corrosion is the process by which materials, usually metals, deteriorate due to chemical reactions with air, moisture, and other agents. During the corrosion of iron (or rusting of iron), iron metal is oxidised by the oxygen of air in the presence of water (moisture) to form hydrated iron (III) oxide called rust:
\[\ce{\underset{Iron}{4Fe} + \underset{Oxygen}{3O2} + \underset{Water}{2xH2O} -> \underset{(Rust)}{\underset{Hydrated iron (III) oxide}{2Fe2O3 * xH2O}}}\]
APPEARS IN
संबंधित प्रश्न
Give two examples of alloys with their chemical composition.
Write two methods of preventing the rusting of iron.
What are alloys?
Two methods by which rusting of iron can be prevented are ______ and ______.
What is anodising? Give its applications.
What special name is given to the corrosion of iron?
The chemical reaction involved in the corrosion of iron metal is that of ______.
In one method of rust prevention, the iron is not coated with anything. Which is this method?
The corrosion of iron is called ______.
Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air.
Compare roasting and calcination.
Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
What is done to prevent corrosion of metals?
_______ forms a green colour in the water.
Match the columns.
| Group A | Group B |
| 1) Electroplating | a) Pressure cooker |
| 2) Anodising | b) Silver plated spoons |
| c) Coating of tin on copper | |
| d) Coating of Zinc on iron |
Write the name.
An alloy of copper and tin-
Observe the following diagram and give answers.
- Name this method of prevention of corrosion.
- For prevention of which metal this method is used?
- What is used as anode in this method?
The process of coating the surface of the metal with a thin layer of zinc is called ______
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.
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
