Match the column :
Metal : Common method of extraction
(i) Aluminium : (a) Electrolysis of oxide dissolved in molten cryolite
(ii) Iron : (b) Roasting followed by reduction with coke
(iii) Copper : (c) Roasting of sulphide partially and reduction
(iv) Zinc : (d) Reduction of the oxide with CO and coke in blast furnace

Question

Accepted Answer

Option 2 is the correct answer for matching the metals with their common methods of extraction. Let's examine why this is the case:

1. **Aluminium: Electrolysis of oxide dissolved in molten cryolite (i)(a)**
   - Aluminium is extracted from its ore, bauxite, which is primarily composed of aluminium oxide (Al₂O₃). The extraction process involves dissolving aluminium oxide in molten cryolite to lower the melting point and then using electrolysis to separate the aluminium metal. This method is known as the Hall-Héroult process and is the most common method for extracting aluminium.

2. **Iron: Reduction of the oxide with CO and coke in blast furnace (ii)(d)**
   - Iron is typically extracted from its ores, such as hematite (Fe₂O₃) or magnetite (Fe₃O₄), using a blast furnace. In this process, the iron ore is reduced by carbon monoxide (CO) and coke (a form of carbon) to produce molten iron. This method is widely used in the steel industry and is known as the blast furnace process.

3. **Copper: Roasting of sulphide partially and reduction (iii)(c)**
   - Copper is often extracted from its sulphide ores, such as chalcopyrite (CuFeS₂), through a process that involves roasting. During roasting, the sulphide ore is heated in the presence of oxygen to convert it into copper oxide and sulphur dioxide. The copper oxide is then reduced to copper metal. This method is commonly used for copper extraction.

4. **Zinc: Roasting followed by reduction with coke (iv)(b)**
   - Zinc is typically extracted from its sulphide ore, zinc blende (ZnS), through a process that involves roasting followed by reduction. The zinc sulphide is first roasted in the presence of oxygen to form zinc oxide (ZnO) and sulphur dioxide. The zinc oxide is then reduced using coke to produce zinc metal. This method is known as the pyrometallurgical process for zinc extraction.

Now, let's explain why the other options are incorrect:

- **Option 1: (i)(a); (ii)(b); (iii)(c); (iv)(d)**
  - This option incorrectly matches iron with roasting followed by reduction with coke (ii)(b), which is not the typical method for iron extraction. Iron is extracted using a blast furnace, as explained above.

- **Option 3: (i)(a); (ii)(c); (iii)(d); (iv)(b)**
  - This option incorrectly matches iron with roasting of sulphide partially and reduction (ii)(c), which is not applicable to iron extraction. Additionally, it incorrectly matches copper with reduction of the oxide with CO and coke in blast furnace (iii)(d), which is not the common method for copper extraction.

- **Option 4: (i)(b); (ii)(a); (iii)(c); (iv)(d)**
  - This option incorrectly matches aluminium with roasting followed by reduction with coke (i)(b), which is not the method used for aluminium extraction. It also incorrectly matches iron with electrolysis of oxide dissolved in molten cryolite (ii)(a), which is not applicable to iron extraction.

In conclusion, Option 2 correctly matches each metal with its common method of extraction, based on established metallurgical processes.