Question

Imagine you are working in the lab and your chemical bottle is labeled Fe2O3. Explain how you could

determine if the iron in the compound is Fe+2 or Fe+3. Provide the name of the compound in your
answer.

Answer 1

To determine the charge of the iron, you must know the charge from the oxygen. An oxygen ion has a -2 charge. Therefore, 3 oxygen ions have -6 charge. We know that charges must cancel out. If it were Fe+2 in the compound, the overall charge would be -2, which isn’t correct. So, we can conclude that it is Fe+3 found in iron (III) oxide.