Answer: Whether a metal oxide can be reduced by a particular reducing agent at a given temperature (comparing free energies of formation).
- A Whether a metal oxide can be reduced by a particular reducing agent at a given temperature (comparing free energies of formation)
- B Generally the precise characteristic colour displayed visually by each freshly purified pure metal sample in general practice
- C Generally the overall industrial rate at which a given target metal can ultimately be extracted from its ore as frequently described
- D Generally the aqueous solubility behaviour shown experimentally by various naturally occurring ore minerals in most textbook accounts
Correct answer: A. Whether a metal oxide can be reduced by a particular reducing agent at a given temperature (comparing free energies of formation)
Explanation: An Ellingham diagram plots Delta_G vs T for metal oxide formation; if the reducing agent's line is below the metal oxide line, reduction is thermodynamically favourable.
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.