Principles and Methods of Extraction — Prelims Questions

Which of the following methods is primarily used for the concentration of sulfide ores?

Which of the following reactions correctly represents calcination?

In the Ellingham diagram, the line for the formation of $\text{CO}$ from $\text{C}$ ($\text{C} + \frac{1}{2}\text{O}_2 \rightarrow \text{CO}$) slopes downwards. What does this indicate?

Which of the following refining methods is based on the principle that impurities are more soluble in the molten state than in the solid state of the metal?

In the Hall-Héroult process for the extraction of aluminium, what is the role of cryolite ($\text{Na}_3\text{AlF}_6$)?

Which of the following metals is refined using the Mond process?