Question

Identify the species oxidized. 2 al3+(aq) + 2 fe(s) → 2 al(s) + 3 fe2+(aq)

Answer 1

To know the answer, compare the oxidation number of the element in the reactant and the product side. The oxidation number of Al was originally +3, then became 0 after the reaction. On the other hand, Fe was originally 0, then became +2 after the reaction. When the element is oxidized, it oxidation number increases. Thus, the element oxidized is Fe.