Q. Identify the reaction that does not take place in a blast furnace?

1. CaCO3 ¾® CaO + CO2
2. 2Fe2O3 + 3C ¾® 4Fe + 3CO2
3. CaO + Si O2 ¾® Ca Si O2 ¾® Ca Si O3
4. CO2 + C ¾® 2CO