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 $..........$ $g \ mol^{-1}$.

List-$I$ contains different compounds formed during the extraction of metal $(M)$ in List-$II$. Match the compounds in List-$I$ with the corresponding metal and process in List-$II$.

List-$I$	List-$II$
$(P). [M(CN)_2]^-$	$(1). Ni$ (during refining of metal)
$(Q). [M(CO)_4]$	$(2). Ti$ (during refining of metal)
$(R). MI_4$	$(3). Pb$ (during roasting of ore)
$(S). MO$	$(4). Ag$ (during leaching of ore)

Which of the following elements constitutes a major impurity in pig iron?

Extraction of copper from copper pyrite $CuFeS_2$ involves:
$A$. Crushing followed by concentration of the ore by froth-flotation
$B$. Removal of iron as slag
$C$. Self-reduction step to produce 'blister copper' following evolution of $SO_2$
$D$. Refining of 'blister copper' by carbon reduction

Consider the following statements:
$(i)$ Froth flotation technique is used to concentrate sulphide ore.
$(ii)$ Froth flotation technique is based upon differential wettability of ore and impurity in water.
$(iii)$ Red Bauxite is concentrated by Bayer's process.
$(iv)$ Carbon is used as a reducing agent during the extraction of zinc from zinc blende.
Which of the following statements are correct?

Which of the following is an incorrect match?