Among the reactions (a) - (d) , the reactions (s) that does /do not occur in the blast furnace during the extraction of iron is / are
(a) `CaO+SiO_2rarrCaSiO_3`
(b) `3Fe_2O_3+COrarr2Fe_3O_4+CO_2`
(c) `FeO+SiO_2rarrFeSiO_3`
(d) `FeOrarrFe+1/2O_2`

Options

A. (c) and (d)
B. (a) and (d)
C. (a)
D. (b)

Answer

To determine which reactions do not occur in the blast furnace during the extraction of iron, we will analyze each of the given reactions (a) to (d).

### Step 1: Analyze Reaction (a)
**Reaction (a):** \( \text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3 \)

- This reaction represents the formation of calcium silicate (slag) from calcium oxide and silica. In the blast furnace, limestone (calcium carbonate) is added, which decomposes to calcium oxide and carbon dioxide. The calcium oxide then reacts with silica (an impurity) to form slag, which is removed.
- **Conclusion:** This reaction occurs in the blast furnace.

### Step 2: Analyze Reaction (b)
**Reaction (b):** \( 3\text{Fe}_2\text{O}_3 + \text{C} \rightarrow 2\text{Fe}_3\text{O}_4 + \text{CO}_2 \)

- This reaction indicates the reduction of iron(III) oxide (Fe2O3) to magnetite (Fe3O4) using carbon. In the blast furnace, iron ores are reduced by carbon monoxide, and this reaction is a part of the reduction process.
- **Conclusion:** This reaction occurs in the blast furnace.

### Step 3: Analyze Reaction (c)
**Reaction (c):** \( \text{FeO} + \text{SiO}_2 \rightarrow \text{FeSiO}_3 \)

- This reaction suggests the formation of iron silicate from ferrous oxide and silica. However, in the blast furnace, the goal is to produce metallic iron, not iron silicate. Ferrous oxide does not react with silica to form iron silicate in the blast furnace.
- **Conclusion:** This reaction does not occur in the blast furnace.

### Step 4: Analyze Reaction (d)
**Reaction (d):** \( \text{FeO} \rightarrow \text{Fe} + \frac{1}{2}\text{O}_2 \)

- This reaction depicts the decomposition of ferrous oxide to produce iron and oxygen. In the blast furnace, ferrous oxide is reduced by carbon monoxide to produce iron and carbon dioxide, not by decomposition. Therefore, this reaction does not occur in the blast furnace.
- **Conclusion:** This reaction does not occur in the blast furnace.

### Final Conclusion
The reactions that do not occur in the blast furnace during the extraction of iron are:
- **(c)** \( \text{FeO} + \text{SiO}_2 \rightarrow \text{FeSiO}_3 \)
- **(d)** \( \text{FeO} \rightarrow \text{Fe} + \frac{1}{2}\text{O}_2 \)

Thus, the answer is **(c) and (d)**.

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