Answer the following questions briefly.
What is the actual reducing agent of haematite in blast furnace ?

Explanation

(i). For iron, first by calcination and roasting the ferrous oxide is oxidised to ferric. Then in blast furnace,
Smelting is done where it is reduced to iron.
`4FeO+O_2to2Fe_2O_3`
`Fe_2O_3+COto2Fe_3O_4+CO_2`
`Fe_2O_3+COto2FeO+CO_2`
`FeO+COtoFe+CO_2`
Carbon monoxide is the actual reducing agent of haematite in blast furnace.
(ii). Zinc is more reducing and cheaper than copper.
(iii). Chalcocite is a sulphide ore of copper therefore it must be roasted in the presence of air to get oxide.