Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?

• Metal sulphides are thermodynamically more stable than CS₂

• CO₂ is thermodynamically more stable than CS₂

• Metal sulphides are less stable than the corresponding oxides

• CO₂ is more volatile than CS₂

What is the significance of leaching in the extraction of aluminium?

Is it true that under certain conditions. Mg can reduce Al₂O₃ and Al can reduce MgO? What are those conditions?

Titanium is a metal of modern times. It is obtained as oxide. Why it could not be extracted earlier despite its wide occurence?

Name the common elements present in the anode mud in electrolytic refining of copper. Why are they so present?

What criterion is followed for the selection of the stationary phase in chromatography?

What is the role of cryolite in the metallurgy of aluminium?

Why is zinc not extracted from zinc oxide through reduction using CO?