Question

In blast furnace, the iron oxide is reduced by:

• A. silica
• B. carbon monoxide
  
• C. carbon
• D. lime stone

Answer 1

The correct option is B carbon monoxide

$CO$ is the main reducing agent in the furnace. Iron oxide is reduced to iron by $CO$.

In a blast furnace, a substance called coke (mainly C) reacts with oxygen, $O_2$, to form carbon monoxide, $CO$. The carbon monoxide (a strong reducing agent) then reacts with iron oxide (in the form of hematite or magnetite) to form pig iron (mainly Fe) and carbon dioxide.

Option B is correct.