Answer: Cu 2 S and FeS.
- A Cu<sub>2</sub>O and FeO
- B Cu and Fe
- C Cu<sub>2</sub>S and FeS
- D CuSO<sub>4</sub> and FeSO<sub>4</sub>
Correct answer: C. Cu<sub>2</sub>S and FeS
Explanation: Smelting the roasted copper ore with silica gives molten matte, a mixture chiefly of cuprous sulfide (Cu<sub>2</sub>S) and ferrous sulfide (FeS).
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.