How many moles of ions are there in 1 mole of iron (III) oxide, Fe2O3?

So one mole of Fe2O3 contains two moles of Fe3+ ions.

Explanation:

As there is an internal mole ratio of 2:3

It means that there are 2moles of iron within every mole of iron(III) oxide.

Iron III oxide is an ionic compound composed of Fe3+ ions and O2- ions. According to the formula, there are three O2- ions for every two Fe3+ ions.

Extra:

One 'unit' of Fe2O3 has two Fe3+ ions and three O2- ions, hence a dozen Fe2O3 contains two dozen Fe3+ ions and three dozen O2- ions, and a mole Fe2O3 contains two moles Fe3+ ions and three moles O2- ions.