Question

In blast furnace iron oxide is reduced by:
A.silica
B.carbon monoxide
C.carbon
D.lime soda

Answer 1

Hint: Iron oxide is reduced by using the blast furnace. Iron ore is available in the form of ${\rm{F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_4}$ and ${\rm{F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_3}$

Complete step by step answer:
The reactions that occur in the blast furnace are as follows.
At the temperature of ${\rm{500^\circ C}}$, the following reaction takes place.
$\begin{array}{l}{\rm{2F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_{\rm{3}}} + {\rm{CO}} \to {\rm{2F}}{{\rm{e}}_{\rm{3}}}{{\rm{O}}_{\rm{4}}} + {\rm{C}}{{\rm{O}}_{\rm{2}}}\\{\rm{F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_{\rm{3}}} + {\rm{CO}} \to {\rm{2FeO}} + {\rm{C}}{{\rm{O}}_{\rm{2}}}\end{array}$
In this reaction, the ferrous trioxide gets reduced to iron oxide.
At the temperature of ${\rm{850^\circ C}}$, the following reaction takes place.
${\rm{F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_{\rm{3}}} + {\rm{CO}} \to 3{\rm{FeO}} + {\rm{C}}{{\rm{O}}_{\rm{2}}}$
In this reaction, the iron oxide gets reduced at ${\rm{850^\circ C}}$.
At the temperature of ${\rm{1000^\circ C}}$, the following reaction takes place.
${\rm{FeO}} + {\rm{CO}} \to {\rm{Fe}} + {\rm{C}}{{\rm{O}}_{\rm{2}}}$
In this reaction, ferrous oxide gets reduced to iron.
At the temperature of ${\rm{1300^\circ C}}$, the following reaction takes place.
${\rm{C}}{{\rm{O}}_2} + {\rm{C}} \to 2{\rm{CO}}$
In this reaction, carbon dioxide is turned into carbon monoxide
At the temperature of ${\rm{1900^\circ C}}$, the following reaction takes place.
${\rm{FeO}} + {\rm{C}} \to {\rm{Fe}} + {\rm{CO}}$

Hence the correct option is B.

Additional information:
Iron oxide occurs naturally as the magnetite mineral. The molar mass of the compound iron oxide is 159.687 g/mol. It is an odorless red-brown solid. There are various applications of the iron oxide. It is used as a catalyst, as pigments, as iron ores, in thermite, and it also occurs in our hemoglobin. Iron oxide is not much expensive and it has a durable property in the paints, colored concrete and in coatings. The hydroxides of iron oxide are iron (II) hydroxide$\left( {{\rm{Fe}}{{\left( {{\rm{OH}}} \right)}_{\rm{2}}}} \right)$ and iron (III) hydroxide $\left( {{\rm{Fe}}{{\left( {{\rm{OH}}} \right)}_3}} \right)$.

Note:
Iron oxide is composed of iron and oxygen atoms. It exists in the form of ${\rm{F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_4}$ and ${\rm{F}}{{\rm{e}}_{\rm{2}}}{{\rm{O}}_3}$. Iron oxide is also called rouge, colcothar, maghemite, rust, iron sesquioxide, ochre etc.