Question

The nuts, bolts, and hinges that attach some gates to a playground fence can be made of iron. The iron can react with oxygen in the air. The unbalanced equation representing this reaction is shown below.
___Fe(s) + ___O2(g) → ___Fe2O3(s)

62 Balance the equation in your answer booklet for the reaction, using the smallest whole-number coefficients. [1]
63 Determine the change in oxidation state for oxygen in this reaction. [1]

Answer 1

The balanced equation is 4Fe(s) + 3O2(g) -> 2Fe2O3(s). For the oxygen, its oxidation state in O2 is 0 and in Fe2O3 is -2. So the oxidation state change from 0 to -2.