Which alloy contains $Cu$,$Sn$ and $Zn$?

Which of the following alloys contains $Sn$ metal?

In the metallurgy of iron,when limestone is added to the blast furnace,the calcium ions end up in:

Match List-$I$ with List-$II$ and select the correct answer using the codes given below the lists :

List-$I$	List-$II$
$(a)$ van Arkel method	$1$. Manufacture of caustic soda
$(b)$ Solvay process	$2$. Purification of titanium
$(c)$ Cupellation	$3$. Manufacture of $Na_2CO_3$
$(d)$ Poling	$4$. Purification of copper
$ $	$5$. Refining of silver

Codes :

Match List-$I$ (substances) with List-$II$ (processes) employed in the manufacture of the substances and select the correct option.

List-$I$ (Substances)	List-$II$ (Processes)
$A$. Sulphuric acid	$i$. Haber's process
$B$. Steel	$ii$. Bessemer's process
$C$. Sodium hydroxide	$iii$. Leblanc process
$D$. Ammonia	$iv$. Contact process

Which among the following statement$(s)$ is(are) true for the extraction of aluminium from bauxite?
$A$. Hydrated $Al_2O_3$ precipitates,when $CO_2$ is bubbled through a solution of sodium aluminate.
$B$. Addition of $Na_3AlF_6$ lowers the melting point of alumina.
$C$. $CO_2$ is evolved at the anode during electrolysis.
$D$. The cathode is a steel vessel with a lining of carbon.