Copper is the most noble of first row transition metals and occurs in small deposits in serveral countries. Ores of copper include chalcanthite `(CuSO_(4).5H_(2)O)`, atacanite `[Cu_(2)Cl(OH)_(3)]`, cuprite `(Cu_(2)O)`, copper glance `(Cu_(2)S)`, and malachite `[Cu_(2)(OH)_(2)CO_(3)]`. However, `80 %` of the world copper production comes from the ore chalcopyrite `(CuFeS_(2))`. The extraction of copper from chalcopyrite involves partial roasting, removal of iron and self-reduction.
Partial roasting of chalcopyrite produces

Options

A. `Cu_(2) S` and `FeO`
B. `Cu_(2) O` and `FeO`
C. `Cu_(2) O` and `Fe_(2) O_(3)`
D. `CuS` and `Fe_(2) O_(3)`.

Answer

A

Explanation

During partial roasting, `CuFeS_(2)` is first converted to `Cu_(2)S` and `FeS`. Further, as iron is more reactive than copper, `FeS` is preferentially oxidised to `FeO`. This partial roasting of chalcopyrite produces `Cu_(2)S` and `FeO`.
`CuFeS_(2) + O_(2) overset (Delta)rarr Cu_(2)S + 2FeS + So_(2)`
`2FeS + O_(2) overset (Delta)rarr Cu_(2)S + 2FeS + SO_(2)`.