Answer: Cinnabar.
- A Galena
- B Cinnabar
- C Bauxite
- D Calamine
Correct answer: B. Cinnabar
Explanation: Cinnabar (HgS) is the chief ore of mercury; galena is a lead ore, bauxite an aluminium ore and calamine a zinc ore.
An Ellingham diagram plots ΔG° of oxide formation against temperature for different metals; whichever line is LOWER (more negative ΔG°) at a given temperature reduces the oxide of any metal whose line sits above it - the basis of carbon reduction (Fe, Zn) vs electrolytic reduction (Al, Mg, Na) decisions.
Concept context
The science of extracting metals from ores and refining them for use. Covers concentration methods, reduction techniques, refining processes, and the thermodynamic principles that govern metal extraction.