The composition of a sample of Wustite is `Fe_(0.93)O_(1.00)`. What fraction of iron is present in the from of `Fe^(2+)` ion ?

Explanation

The ratio of the Fe and O atoms in pure iron oxide (FeO) = `1:1`
Let x atoms of Fe(II) be replaced by Fe(III) in Wustite.
`therefore` No. of Fe(II) atoms present = `(0.93-x)`
Since the oxide is neutral,
Total charge on iron atoms = Charge on oxygen atom
`2(0.93-x)+3x=2`
`1.86-2x+3x=2`
`x=2-1.86=0.14`
No. of `Fe^(3+)` ions in the sample = 0.14
No. of `Fe^(2+)` ions in the sample = `0.93-0.14=0.79`
Fraction of `Fe^(2+)` ions in the sample `=(0.79)/(0.93)=0.85`