German silver is an alloy of

Match the items under List-$I$ with the compounds/elements from the List-$II$. Select the correct answer from the sets $(a), (b), (c)$ and $(d)$.

List-$I$	List-$II$
$(i)$ Explosive	$(A)$ $NaN_3$
$(ii)$ Artificial gem	$(B)$ $Fe_3O_4$
$(iii)$ Self reduction	$(C)$ $Sn$
$(iv)$ Magnetic material	$(D)$ $Al_2O_3$
	$(E)$ $Pb(N_3)_2$
	$(F)$ $Fe_2O_3$
	$(G)$ $Cu$
	$(H)$ $SiC$

German silver does not contain

Given below are two statements:
Statement $I$: During electrolytic refining,the pure metal is made to act as anode and its impure metallic form is used as cathode.
Statement $II$: During the Hall-Heroult electrolysis process,purified $Al_2O_3$ is mixed with $Na_3AlF_6$ to lower the melting point of the mixture.
In the light of the above statements,choose the most appropriate answer from the options given below:

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.

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. Concentration of gold ore	$I$. Aniline
$B$. Leaching of alumina	$II$. $NaOH$
$C$. Froth stabiliser	$III$. $SO_2$
$D$. Blister copper	$IV$. $NaCN$

Choose the correct answer from the options given below.