In the determination of iron in an ore, the ore (mostly Fe2O3) is first dissolved in HCl (aq). A slight excess of Sn2 is added to reduce Fe3 to Fe2. Enter the net ionic equation for the redox reaction.

2Fe⁺³ + Sn₂ → 2Fe⁺² + 2Sn⁺²

Explanation:

A redox reaction occurs between a compound that loses electrons and others that gain an electron. The first is being oxidized, and the other is being reduced.

In this situation, in the compound Fe₂O₃, the iron, has an oxidation number equal to + 3, so it's Fe⁺³, and it will gain 1 electron to become Fe⁺². Because it was first dissolved in HCl, we must use the ion at the equation. The other compound Sn₂ will be oxidized to Sn⁺², so it will need to lose 2 electrons.

So, it will be necessary 2 Fe⁺³ for this reaction happen:

2Fe⁺³ + Sn₂ → 2Fe⁺² + 2Sn⁺²