Aluminium is extracted from alumina $Al_2O_3$ by electrolysis of a molten mixture of

The reactions which occur in a blast furnace at $500-800 \ K$ during the extraction of iron from haematite are:
$(i)$ $3 Fe_2O_3 + CO \rightarrow 2 Fe_3O_4 + CO_2$
$(ii)$ $Fe_2O_3 + 3 C \rightarrow 2 Fe + 3 CO$
$(iii)$ $Fe_3O_4 + 4 CO \rightarrow 3 Fe + 4 CO_2$
$(iv)$ $Fe_2O_3 + CO \rightarrow 2 FeO + CO_2$

In the smelting of iron,which of the following reactions takes place in the blast furnace at $400\,^{\circ}C - 600\,^{\circ}C$?

In Hall’s process,the main reagent is mixed with

In which of the following isolations is no reducing agent required?

$Aluminium$ oxide is not reduced by chemical reactions since: