Question

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

• A. $CaO+Si{O}_2\to CaSi{O}_3$
• B. $2C{u}_{2}S+3O_2\to 2C{u}_{2}O+2S{O}_2$
• C. $FeO+Si{O}_2\to FeSi{O}_3$
• D. $2FeS+3O_2\to 2FeO+2S{O}_2$

Answer 1

Answer: (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 $Cu$.