Which method is used to obtain $Al$ from $Al_2O_3$?

Extraction of gold and silver involves leaching with $CN^{-}$ ion. Silver is later recovered by

In the extraction of copper,the slag obtained is mainly composed of........

Which of the following is incorrect on the basis of the Ellingham diagram for carbon?

In which of the following pairs of metals are both commercially extracted from their respective ores by the carbon reduction method?

Given below are two statements.
Statement $I:$ The choice of reducing agents for metals extraction can be made by using Ellingham diagram,a plot of $\Delta G$ vs temperature.
Statement $II:$ The value of $\Delta S$ increases from left to right in Ellingham diagram.
In the light of the above statements,choose the most appropriate answer from the options given below: