Question

Which of the statements about the following reactions is correct?

$\mathrm{ZnO}+\mathrm{CO}\to \mathrm{Zn}+{\mathrm{CO}}_2$

• A. $ZnO$ is being oxidized.
• B. $CO$ is being reduced.
• C. ${CO}_2$ is being oxidized.
• D. $ZnO$ is being reduced.

Answer 1

The correct option is D

$\mathrm{ZnO}$ is being reduced.

Solution:

Explanation for correct option:

(D):

• The reaction corresponding to the gain of Oxygen ($\mathrm{O}$) or loss of Hydrogen ($\mathrm{H}$) by a species is called an oxidation reaction. On the other hand, the reaction corresponding to the loss of Oxygen or gain of Hydrogen by a species is called a reduction reaction.
• $\mathrm{ZnO}\left(\mathrm{s}\right)+\mathrm{CO}\left(\mathrm{g}\right)\to \mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$
• In this reaction, Zinc oxide ($\mathrm{ZnO}$) loses oxygen $\left(\mathrm{O}\right)$ and forms Zinc ($\mathrm{Zn}$). Hence, $\mathrm{ZnO}$ is getting reduced.

Explanation for incorrect options:

(A) Since, Zinc oxide ($\mathrm{ZnO}$) loses $\mathrm{O}$ and forms Zinc ($\mathrm{Zn}$), it is being reduced and not oxidized.

(B) Since in the reaction $\mathrm{ZnO}\left(\mathrm{s}\right)+\mathrm{CO}\left(\mathrm{g}\right)\to \mathrm{Zn}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$, an Oxygen atom is being added to Carbon monoxide ($\mathrm{CO}$) to form Carbon dioxide (${\mathrm{CO}}_2$), thus it is getting oxidized.

(C) ${\mathrm{CO}}_2$ is formed due to the reduction of $\mathrm{CO}$.

Final answer:

Hence, option (D) is correct. $\mathrm{ZnO}$ is being reduced.