In the extraction of copper,metal is formed in the Bessemer converter due to the reaction:

In the electrolytic extraction of aluminum,molten cryolite $(Na_3AlF_6)$ is used to:

Which process of reduction of mineral to the metal is suited for the extraction of copper from its ores with low copper content?

Which oxide formation according to the Ellingham diagram shows a graph with a sudden change in slope?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ In an Ellingham diagram,the oxidation of carbon to carbon monoxide shows a negative slope with respect to temperature.
Reason $R:$ $CO$ tends to get decomposed at higher temperature.
In the light of the above statements,choose the correct answer from the options given below:

During the electrolytic reduction of alumina,two auxiliary electrolytes $X$ and $Y$ are added to increase the electrical conductance and lower the melting point of the mixture. $X$ and $Y$ are: