During the extraction of $Fe$,the slag obtained is:

Thermite is a mixture of iron oxide and which of the following?

In the alumino-thermite process,$Al$ acts as which of the following substances?

The purpose of smelting of an ore is

Iron can be obtained on a large scale from $Fe_2O_3$ by which of the following methods?

In the process of extraction of gold,roasted gold ore reacts as follows. Identify the complexes $[X]$ and $[Y]$:
$\text{Roasted gold ore} + CN^{-} + H_2O \xrightarrow{O_2} [X] + OH^{-}$
$[X] + Zn \to [Y] + Au$