Match the column:

Options

A. `{:(Column I, ColumnII),(PbS rarr PbO,(p)"Roasting"):}`
B. `{:(Column I, ColumnII),(CaCO_(3) rarr CaO ,(q)"Calcination"):}`
C. `{:(Column I, ColumnII),(ZnS rarr Zn ,(r)"Carbon reduction"):}`
D. `{:(Column I, ColumnII),(Cu_(2)S rarr Cu ,(s)"Self reduction"):}`

Answer

To solve the matching question related to the conversion processes in metallurgy, we will analyze each part of the question step by step.

### Step-by-Step Solution:

1. **Identify the Processes for PbS to PbO:**
- The conversion of lead sulfide (PbS) to lead oxide (PbO) occurs through a reaction with oxygen.
- The balanced reaction is:
\[ 2 \text{PbS} + 3 \text{O}_2 \rightarrow 2 \text{PbO} + 2 \text{SO}_2 \]
- This process is known as **roasting**, which involves converting a sulfide ore to its corresponding oxide in the presence of air.

**Match: A → P (Roasting)**

2. **Identify the Processes for CaCO3 to CaO:**
- The conversion of calcium carbonate (CaCO3) to calcium oxide (CaO) occurs through heating, resulting in the release of carbon dioxide (CO2).
- The balanced reaction is:
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
- This process is known as **calcination**, which involves the thermal decomposition of carbonate ores in the absence of air.

**Match: B → Q (Calcination)**

3. **Identify the Processes for ZnS to Zn:**
- The conversion of zinc sulfide (ZnS) to zinc (Zn) involves two steps:
1. Roasting ZnS to form zinc oxide (ZnO):
\[ 2 \text{ZnS} + 3 \text{O}_2 \rightarrow 2 \text{ZnO} + 2 \text{SO}_2 \]
2. Reducing ZnO to Zn using carbon:
\[ \text{ZnO} + \text{C} \rightarrow \text{Zn} + \text{CO} \]
- The first step is roasting, and the second step is carbon reduction (smelting).

**Match: C → R (Roasting and Carbon Reduction)**

4. **Identify the Processes for Cu2S to Cu:**
- The conversion of copper(I) sulfide (Cu2S) to copper (Cu) also involves two steps:
1. Roasting Cu2S to form copper(I) oxide (Cu2O):
\[ 2 \text{Cu}_2\text{S} + 3 \text{O}_2 \rightarrow 2 \text{Cu}_2\text{O} + 2 \text{SO}_2 \]
2. The remaining unreacted Cu2S can react with Cu2O to produce copper:
\[ \text{Cu}_2\text{S} + 2 \text{Cu}_2\text{O} \rightarrow 6 \text{Cu} + \text{SO}_2 \]
- The first step is roasting, and the second step involves self-reduction.

**Match: D → S (Roasting and Self-Reduction)**

### Final Matching:
- A → P (Roasting)
- B → Q (Calcination)
- C → R (Roasting and Carbon Reduction)
- D → S (Roasting and Self-Reduction)