Answer: 2Cu2O + Cu2S → 6Cu + SO2.
- A 2Cu2O + Cu2S → 6Cu + SO2
- B Cu2S + 2O2 → 2CuO + SO2
- C CuO + C → Cu + CO
- D 2Cu + O2 → 2CuO
Correct answer: A. 2Cu2O + Cu2S → 6Cu + SO2
Explanation: After part of the Cu2S is oxidised to Cu2O, the two react together in self-reduction: 2Cu2O + Cu2S gives 6Cu + SO2.
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.