Question

The number of iron atom(s) in Fe$_3$O$_4$ with an oxidation state of III along with a coordination number of six is _ _ _. (answer in integer)

Hint:

In inverse spinel structures like Fe$_3$O$_4$, Fe$^{3+}$ ions occupy both tetrahedral and octahedral sites

Answer 1

Correct Answer: 1

Step 1: Structure of magnetite.
Fe$_3$O$_4$ is an inverse spinel with one Fe$^{2+}$ and two Fe$^{3+}$.

Step 2: Site of each ion.
One Fe$^{3+}$ sits in a tetrahedral site with coordination number four, the other Fe$^{3+}$ sits in an octahedral site with coordination number six.

Step 3: Apply the condition.
Only one Fe$^{3+}$ has the plus three state together with coordination number six.

Step 4: Answer.
\[ \boxed{1} \]