Question

Which of the following statements about the given reaction are correct?

$3\mathrm{Fe}\left(\mathrm{s}\right)+4{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\to {\mathrm{Fe}}_3{\mathrm{O}}_4\left(\mathrm{s}\right)+4{\mathrm{H}}_2\left(\mathrm{g}\right)$

(i) Iron metal is getting oxidised

(ii) Water is getting reduced

(iii) Water is acting as a reducing agent

(iv) Water is acting as an oxidising agent

• A. (i), (ii) and (iii)
• B. (iii) and (iv)
• C. (i), (ii) and (iv)
• D. (ii) and (iv)

Answer 1

The correct option is C

(i), (ii) and (iv)

Explanation for the correct option:

C) (i), (ii) and (iv)

• Oxidation in terms of Oxygen ($\mathrm{O}$) can be defined as the addition of Oxygen. So that Iron ($\mathrm{Fe}$) is oxidized due to the addition of Oxygen forming Iron(II, III) oxide $\left({\mathrm{Fe}}_3{\mathrm{O}}_4\right)$.
• Reduction in terms of Oxygen ($\mathrm{O}$) can be defined as the removal of Oxygen. So that Water $\mathrm{\left(}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}\mathrm{\right)}$ is getting reduced due to the removal of Oxygen from Water and forming Hydrogen gas $\mathrm{\left(}{\mathrm{H}}_{\mathrm{2}}\mathrm{\right)}$.
• An oxidizing agent is the species that oxidize the other substance and reduces itself. Water $\mathrm{\left(}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}\mathrm{\right)}$ oxidizes $\mathrm{Fe}$ and itself reduces to form Hydrogen gas.

Explanation for the incorrect options:

A) (i), (ii) and (iii)

• The first two statements are correct but the third statement is wrong. Water is not a reducing agent, because Water is getting reduced and it is oxidizing the Iron.
• A reducing agent is a species that reduces other substances and oxidizes itself.

B) (iii) and (iv)

• Water cannot act as both oxidizing and reducing agent. Hence in this case water act as a reducing agent.

D) (ii) and (iv)

• The two statements are correct.
• Water $\mathrm{\left(}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}\mathrm{\right)}$ is getting reduced due to the removal of Oxygen from Water and forming Hydrogen gas $\mathrm{\left(}{\mathrm{H}}_{\mathrm{2}}\mathrm{\right)}$.
• An oxidizing agent is the species that oxidize the other substance and reduces itself. Water $\mathrm{\left(}{\mathrm{H}}_{\mathrm{2}}\mathrm{O}\mathrm{\right)}$ oxidizes $\mathrm{Fe}$ and itself reduces to form Hydrogen gas

Hence, option (C) is correct.