In the extraction of iron from hematite,what is the role of limestone?

Which of the following reactions is an example of roasting?

Select the process in which $SO_2$ is $NOT$ evolved:

Select the correct statement:

Choose the correct code regarding the Roasting process.
$I$. It is the process of heating ore in air to obtain the oxide.
$II$. It is an exothermic process.
$III$. It is used for hydrated oxide and oxysalt ore.
$IV$. It is used after the concentration of ore.

Sulphide ore on roasting gives a gas $X$. $X$ reacts with $Cl_{2}$ in the presence of activated charcoal to give $Y$. $Y$ is