Question

The composition of a sample of wustite is ${Fe}_{0.93}{O}_{100}$. What percentage of iron is present in the form of $Fe\left(III\right)$?

• A. 25%
• B. 12%
• C. 33%
• D. 15%

Answer 1

The correct option is D 15%

Assuming $Fe$ occurring as +3 state be $a$ and occurring as +2 state will be $(0.93-a)$.
$3a+2(0.93-a)=2$ $3a+1.86-2a=2$ $a=0.14$. Percentage of $Fe\left(III\right)=\frac{0.14}{0.93}\times 100=15$.