Copper is the most noble of the first row transition metals and occurs in small deposits in several countries. Ores of copper inculcated chalcanthite (CuSO$$_4$$ . 5H$$_2$$O), atacamite (Cu$$_2$$Cl(OH)$$_3$$), cuprite (Cu$$_2$$O), copper glance (Cu$$_2$$S) and malacite (Cu$$_2$$(OH)$$_2$$CO$$_3$$). However, 80% of the world copper production comes from the ore of chalcopyrite (CuFeS$$_2$$). The extraction of copper from chalcopynite involves partial roasting, removal of iron and self-reduction.
Iron is removed from chalcopyrite as
Copper is the most noble of the first row transition metals and occurs in small deposits in several countries. Ores of copper inculcated chalcanthite (CuSO$$_4$$ . 5H$$_2$$O), atacamite (Cu$$_2$$Cl(OH)$$_3$$), cuprite (Cu$$_2$$O), copper glance (Cu$$_2$$S) and malacite (Cu$$_2$$(OH)$$_2$$CO$$_3$$). However, 80% of the world copper production comes from the ore of chalcopyrite (CuFeS$$_2$$). The extraction of copper from chalcopynite involves partial roasting, removal of iron and self-reduction.
In self-reduction, the reducing species is
Match the conversions in Column I with the type(s) of reaction(s) given in Column II. Indicate your answer by darkening the appropriate bubbles of the 4 $$\times$$ 4 matrix given in the ORS.
| Column I | Column II | ||
|---|---|---|---|
| (A) | PbS $$\to$$ PbO | (P) | roasting |
| (B) | CaCO$$_3$$ $$\to$$ CaO | (Q) | Calcination |
| (C) | ZnS $$\to$$ Zn | (R) | carbon reduction |
| (D) | Cu$$_2$$S $$\to$$ Cu | (S) | self reduction |
Native silver metal forms a water soluble complex with a dilute aqueous solution of NaCN in the presence of: