Type metal is an alloy of $Pb, Sb$ and $Sn$. It consists of

Select the incorrect statement.

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

Among statements $(a)-(d),$ the correct ones are
$(a)$ Limestone is decomposed to $CaO$ during the extraction of iron from its oxides.
$(b)$ In the extraction of silver,silver is extracted as an anionic complex.
$(c)$ Nickel is purified by Mond's process.
$(d)$ $Zr$ and $Ti$ are purified by Van Arkel method.

The correct option$(s)$ related to the extraction of iron from its ore in the blast furnace operating in the temperature range $900-1500 \ K$ is(are):
$(A)$ Limestone is used to remove silicate impurity.
$(B)$ Pig iron obtained from blast furnace contains about $4 \%$ carbon.
$(C)$ Coke $(C)$ converts $CO_2$ to $CO$.
$(D)$ Exhaust gases consist of $NO_2$ and $CO$.

Which of the following statements is not correct?