Question

A black powdery substance used for the reduction of zinc oxide during extraction.

Answer 1

• A black powdery substance used for the reduction of zinc oxide during extraction is called coke.
• Coke reduced zinc oxide on heating to give zinc metal along with carbon dioxide $\left({\mathrm{CO}}_2\right)$.

$$\begin{gathered} 2\mathrm{ZnO}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right)\underset{673\mathrm{K}}{\overset{∆}{\to }}2\mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right) \\ \mathrm{zinc}\mathrm{oxide}\mathrm{coke}\mathrm{zinc}\mathrm{metal}\mathrm{carbon}\mathrm{dioxide} \end{gathered}$$

• Coke is a better reducing agent to reduce zinc oxide $\left(\mathrm{ZnO}\right)$.

Hence, Coke is a black powdery substance used for the reduction of zinc oxide during extraction.