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 Fe O
C. CuS and `Fe_2O_ 3 `
D. `Cu_2O and Fe_2 O _ 3 `

Answer

A

Explanation

During partial roasting, ` Cu Fe S _ 2 ` is first converted into a mixture of ` Cu_ 2 S ` and FeS. Further, since iron is more reactive than Cu, therefore, FeS is preferentially oxidised to FeO. Thus, partial roasting of chalcopyrite produces ` Cu _ 2 S ` and FeO.
` underset ("Chalcopyrite")( 2Cu Fe S_ 2 ) + O _ 2 overset (Delta ) to Cu_ 2 S + 2 Fe S + SO _ 2 `
` 2 FeS + 3 O _ 2 overset (Delta ) to 2 FeO + 2 SO _ 2 `
Thus, option (a) is correct.