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

$I$. $FeCr_2O_4 + NaOH + \text{air} \rightarrow Na_2CrO_4 + Fe_2O_3$
$II$. $Na_2CrO_4 + H_2SO_4 \rightarrow Na_2Cr_2O_7$
$Na_2CrO_4$ and $Fe_2O_3$ are separated by:

In the metallurgical extraction of copper,the following reaction is used:
$FeO + SiO_{2} \rightarrow FeSiO_{3}$
$FeO$ and $FeSiO_{3}$ respectively are:

The Ellingham diagram represents:

Which series of reactions correctly represents chemical reactions related to iron and its compounds?

$I$. $FeCr_2O_4 + NaOH + \text{air} \rightarrow (A) + Fe_2O_3$
$II$. $(A) + (B) \rightarrow Na_2Cr_2O_7$
$III$. $Na_2Cr_2O_7 + X \xrightarrow{\Delta} Cr_2O_3$
$IV$. $Cr_2O_3 + Y \xrightarrow{\Delta} Cr$
High temperature $(> 1000 \ ^\circ C)$ electrolytic reduction is necessary for isolating: