The reaction for obtaining the metal $(M)$ from its oxide $(M_{2}O_{3})$ ore is given by
$M_{2}O_{3(s)} + 2 Al(\ell) \xrightarrow{\text{Heat}} Al_{2}O_{3}(\ell) + 2 M_{(s)}$,$(s = \text{solid}, \ell = \text{liquid})$
In this case,$M$ is

In the manufacture of iron from haematite,the function of limestone is as

Statement $I :$ Leaching of gold with cyanide ion in absence of air $/$ $O_2$ leads to cyano complex of $Au(III)$.
Statement $II :$ Zinc is oxidized during the displacement reaction carried out for gold extraction.
In the light of the above statements,choose the correct answer from the options given below.

In the extraction of iron from haematite,the impurity $(x)$ of the ore is removed in the form of '$y$'. What are $x$ and $y$ respectively?

In the $Down's$ process,why is $CaCl_2$ added to $NaCl$?

In the production of iron,limestone is added to the blast furnace. At the end of the process,the $Ca$ ion is in the form of.......