Question

Due to metal deficiency defect, iron forms a non-stoichiometric composition in which iron is present in +2 and +3 oxidation state. In this oxide 15% iron is present in +3 oxidation state. In this oxide 15% iron is present in +3 oxidation state. The formula of oxide is:

• A. $\text{F}{\text{e}}_{\text{0}\text{.93}}\text{O}$
• B. $\text{F}{\text{e}}_{\text{0}\text{.96}}\text{O}$
• C. $\text{F}{\text{e}}_{\text{0}\text{.98}}\text{O}$
• D. $\text{F}{\text{e}}_{\text{0}\text{.99}}\text{O}$

Answer 1

The correct option is A $\text{F}{\text{e}}_{\text{0}\text{.93}}\text{O}$

Charge of Iron must balance the charge of oxygen.

Let the formula be $F{e}_{x}O$

$2(x-\frac{3x}{20})+3\left(\frac{3x}{20}\right)=2$

$⟹\frac{2\left(17x\right)}{20}+\frac{9x}{20}=2$

$⟹\frac{43x}{20}=2$

$⟹x=0.93$

Formula of oxide: $F{e}_{0.93}O$