Question

Analysis show that iron oxide consist of Iron ion with $94\%$ ions having $d^{6}$ configuration and $6\%$ having $d^{5}$ configuration. Which amongst the following best represents the formula of the oxide?

• A. $Fe_{0.97}O$
• B. $ \, Fe_{1.03}O$
• C. $ \, Fe_{0.60}O$
• D. $ \, Fe_{0.94}O_{0.94}$

Answer 1

Answer: (A)

$d^{6} \rightarrow Fe^{+ 2},d^{5} \rightarrow Fe^{+ 3}$

Total charge of Iron

$=\left(0.94 \times 2\right)+\left(0.06 \times 3\right)=1.88+0.18=2.06$

Number of $O^{- 2}ion=\frac{2.06}{2}=1.03$

Formula of solid $=FeO_{1.03}=Fe_{0.97}O$