# Among the reactions (a) - (d),

Question:

Among the reactions (a) - (d), the reaction(s) that does/do not occur in the blast furnace during the extraction of iron is/are:

(a) $\mathrm{CaO}+\mathrm{SiO}_{2} \rightarrow \mathrm{CaSiO}_{3}$

(b) $3 \mathrm{Fe}_{2} \mathrm{O}_{3}+\mathrm{CO} \rightarrow 2 \mathrm{Fe}_{3} \mathrm{O}_{4}+\mathrm{CO}_{2}$

(c) $\mathrm{FeO}+\mathrm{SiO}_{2} \rightarrow \mathrm{FeSiO}_{3}$

(d) $\mathrm{FeO} \rightarrow \mathrm{Fe}+\frac{1}{2} \mathrm{O}_{2}$

1. (a)

2. (a) and (d)

3. (c) and $(\mathrm{d})$

4. (d)

Correct Option: , 3

Solution:

During the reduction of $\mathrm{Fe}_{2} \mathrm{O}_{3}$ to $\mathrm{FeO}$,

$\mathrm{Fe}_{2} \mathrm{O}_{3}$ is first reduced to $\mathrm{Fe}_{3} \mathrm{O}_{4}$ and then to $\mathrm{FeO}$, thus follows reaction (b).

In order to remove impurity of the ore limestone is added along with ore which is decomposed to $\mathrm{CaO}$.

The resulted $\mathrm{CaO}$ reacts with $\mathrm{SiO}_{2}$ to form $\mathrm{CaSiO}_{3}$ i.e. follows reaction (a) and is removed as a slag.