JEE Advanced2021ChemistryGeneral Principles and Processes of Isolation of MetalsActual
The correct statement s related to the metal extraction processes is(are)
Options
- AA mixture of PbS and PbO undergoes self-reduction to produce Pb and SO 2 .
- BIn the extraction process of copper from copper pyrites, silica is added to produce copper silicate.
- CPartial oxidation of sulphide ore of copper by roasting, followed by self-reduction produces blister copper.
- DIn cyanide process, zinc powder is utilized to precipitate gold from Na Au CN 2 .
Correct answer
A. A mixture of PbS and PbO undergoes self-reduction to produce Pb and SO 2 .
Step-by-step solution
A PbS + PbO → Pb + SO 2 It is self-reduction reaction. B In the extraction process of copper from copper pyrites, silica is added to produce Iron silicate. C Partial oxidation of sulphide ore of copper by roasting, followed by self-reduction produces blister copper. Cu 2 S + O 2 → Cu 2 O + SO 2 Cu 2 S + 2 Cu 2 O → self − reduction 6 Cu + SO 2 D Zn + 2 Na Au CN 2 → Na 2 Zn CN 4 + 2 Au