When silica is present as an impurity in an ore,a/an ........ flux is required.

In the metallurgical extraction of copper,the following reaction is used:
$FeO + SiO_{2} \rightarrow FeSiO_{3}$
$FeO$ and $FeSiO_{3}$ respectively are:

During the electrolytic reduction of alumina,the reaction at the cathode is:

Given below are two statements.
Statement $I$: According to the Ellingham diagram,any metal oxide with higher $\Delta G^{\circ}$ is more stable than the one with lower $\Delta G^{\circ}$.
Statement $II$: The metal involved in the formation of oxide placed lower in the Ellingham diagram can reduce the oxide of a metal placed higher in the diagram.
In the light of the above statements,choose the correct answer from the options given below.

For the formation of which compound in the Ellingham diagram does $\Delta G^{\circ}$ become more and more negative with an increase in temperature?

In the isolation of which one of the following metals from their ores,is the use of cyanide salt not commonly involved?