# How many moles of iron are in 0.067 gram sample of iron oxide?

Well if its $\text{ferric oxide}$..........
$\text{Ferric oxide}$, $F {e}_{2} {O}_{3}$, has a molar mass of $159.69 \cdot g \cdot m o {l}^{-} 1$.
$\text{Moles of ferric oxide} = \frac{0.067 \cdot g}{159.69 \cdot g \cdot m o {l}^{-} 1} = 4.20 \times {10}^{-} 4 m o l$.
Of course it could be $\text{ferrous oxide}$, $F e O$, or another iron oxide, so I don't think that this question was well-proposed.