Which metal is added to recover $Au$ from $[Au(CN)_2]^-$?

Which of the following fluxes is used to remove acidic impurities during metallurgy?

The value of ${\Delta _r}{G^\Theta }$ for the formation of $Cr_2O_3$ is $-540 \, kJ \, mol^{-1}$ and that of $Al_2O_3$ is $-827 \, kJ \, mol^{-1}$. Is the reduction of $Cr_2O_3$ possible with $Al$?

Which of the following is obtained as a slag during the extraction of iron from iron oxide?

Choose the correct option with reference to the following statements:
$(1)$ Pig iron is produced at a temperature of $1270 \ K$.
$(2)$ Pig iron contains $4 \%$ carbon.
$(3)$ Pig iron cannot be cast into a variety of shapes.
$(4)$ Pig iron contains small amounts of impurities like $P, S, Si, Mn$.

Iron can be obtained on a large scale from $Fe_2O_3$ by which of the following methods?