Exams › JEE Advanced › Chemistry
Which of the following reactions represents an example of the reduction of a calcined or roasted ore to obtain the metal?
- Bauxite ore + Na2CO3 (fused) -> NaAlO2
- Ag2S + NaCN <=> Na[Ag(CN)2] + Na2S
- ZnO + C -> Zn + CO
- CuSO4(aq.) + Zn dust -> ZnSO4 + Cu
Correct answer: ZnO + C -> Zn + CO
Solution
ZnS (zinc blende) is first roasted to ZnO (calcined ore), then ZnO is reduced by coke (C) at high temperature: ZnO + C -> Zn + CO. This is the classic example of reduction of a roasted/calcined ore. The other options represent fusion, leaching (hydrometallurgy), and cementation respectively.
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