Which one of the following oxides is reduced by water gas to obtain the metal during its extraction?
Which one of the following oxides is reduced by water gas to obtain the metal during its extraction?
$\mathrm{NiO}$
$\mathrm{ZnO}$
$\mathrm{WO}_3$
$\mathrm{Fe}_2 \mathrm{O}_3$
Solution
Nickel oxide is reduced by water gas to obtain the metal. Other oxides are reduced by other reducing agent.
$\begin{gathered}
\mathrm{ZnO}+\mathrm{C} \stackrel{\Delta}{\longrightarrow} \mathrm{Zn}+\mathrm{CO} \\
\mathrm{WO}_3+3 \mathrm{H}_2 \stackrel{\Delta}{\longrightarrow} \mathrm{W}+3 \mathrm{H}_2 \mathrm{O} \\
\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{CO} \stackrel{\Delta}{\longrightarrow} 2 \mathrm{Fe}+3 \mathrm{CO}_2 \\
2 \mathrm{NiO}+\underbrace{\mathrm{CO}+\mathrm{H}_2}_{\text {Water gas }} \longrightarrow 2 \mathrm{Ni}+\mathrm{CO}_2+\mathrm{H}_2 \mathrm{O}
\end{gathered}$