In the extraction of which of the following metals is a complex salt formed?

Aluminium is prepared in large quantities by

Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?

Smelting is termed to the process in which

Which of the following is $NOT$ an extraction process for silver?

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