Question

Which one of the following reactions does not occur during extraction of copper?

• A. $CaO + SiO _2 \rightarrow CaSiO _3$
• B. $2 Cu _2 S +3 O _2 \rightarrow 2 Cu _2 O +2 SO _2$
• C. $FeO + SiO _2 \rightarrow FeSiO _3$
• D. $2 FeS +3 O _2 \rightarrow 2 FeO +2 SO _2$

Answer 1

Answer: (A)

$CaO + SiO _2 \rightarrow CaSiO _3$

Answer 2

CuFeS2​+O2​ Partial roasting ​
Cu2​S+FeO+SO2​+ very small FeS​+very smallCu2​O​
Cu2​S+O2​→Cu2​O+SO2​
FeS+O2​→FeO+SO2​
FeO+SiO2​→FeSiO3​
No formation of calcium silicate (CaSiO3​) in extraction of Cu.

So, the correct option is (A): $CaO + SiO _2 \rightarrow CaSiO _3$