Name the reagent that is used in leaching of gold.

The purification of alumina is called

Froth floatation process is used for the concentration of

Which method is used for the concentration of cassiterite ore?

Which substances are used as stabilizers in the froth flotation process?

Observe the following statements regarding the purification of bauxite:
$I$. During Hall's process,silica is removed as $Si$ (vapour).
$II$. Bauxite ore contaminated with $Fe_2O_3$ is purified in Baeyer's process.
$III$. During Serpeck's process,$AlN$ is formed.
The correct answer is: