A sample of wustite has the composition Fe_0.92O. Assuming only Fe^2+ and Fe^3+ are present, the percentage of iron present as Fe^3+ is

JEE Advanced levelSingle correct optionDifficulty 3 of 3ss102

A sample of wustite has the composition $Fe X_{0.92} O$ . Assuming only $Fe X^{2 +}$ and $Fe X^{3 +}$ are present, the percentage of iron present as $Fe X^{3 +}$ is

Let

Fe X^{3 +}

x

per O. Charge balance:

3 x + 2 (0.92 - x) = 2

, so

x = 0.16

. Fraction

= 0.16/0.92 = 0.1739

, i.e. 17.4%.