The molar mass of the water-insoluble product formed from the fusion of chromite ore $(FeCr_2O_4)$ with $Na_2CO_3$ in the presence of $O_2$ is $..........$ $g \ mol^{-1}$.

Identify the reaction,which is not related to the extraction of copper.

Given below are two statements.
Statement $I$: Pig iron is obtained by heating cast iron with scrap iron.
Statement $II$: Pig iron has a relatively lower carbon content than that of cast iron.
In the light of the above statements,choose the correct answer from the options given below.

The smelting of iron in the blast furnace involves all the following processes except:

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

List-$I$	List-$II$
$I.$ Cyanide process	$(1)$ Ultrapure $Ge$
$II.$ Floatation process	$(2)$ Dressing of $HgS$
$III.$ Electrolytic reduction	$(3)$ Extraction of $Al$
$IV.$ Zone refining	$(4)$ Extraction of $Au$

Which of the following processes is $NOT$ involved in the extraction of metal from cassiterite $(SnO_2)$ ore?