Copper is the most noble among the first row transition metals and occurs in small deposits in several countries. Ores of copper include chalcopyrite `(CuFeS_(2))`, cuprite `(Cu_(2)O)`, copper glance `(Cu_(2)S)` and malachite `[CyCO_(3).Cu(OH)_(2)]`. 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 ironand self-reduction.
In self-reduction, the reducing species is

Options

A. S
B. `O^(2-)`
C. `S^(2-)`
D. `SO_(2)`

Answer

C

Explanation

They get oxidised to `SO_(2)`. Here `S^(2-)` ions are the reducing agent.