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

The Correct Option is A

$CuFe{S}_2+O_2\stackrel{\text{Partial roasting}}{\to }$
$C{u}_{2}S+FeO+S{O}_2+\underset{\text{very small}}{\mathrm{FeS}}+\underset{\text{very small}}{C{u}_{2}O}$
$C{u}_{2}S+O_2\to C{u}_{2}O+S{O}_2$
$FeS+O_2\to FeO+S{O}_2$
$FeO+Si{O}_2\to FeSi{O}_3$
No formation of calcium silicate $\left(CaSi{O}_3\right)$ in extraction of $Cu$.

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