The equation Fe + 3Fe3O4 -> 4Fe2O3

The chemical equation above describes the reaction process of iron (Fe) with iron(II,III) oxide (Fe₃O₄) to create iron(III) oxide (Fe₂O₃). In this equation, 1 mol of iron reacts with 3 mol of Fe₃O₄ to produce 4 mol of Fe₂O₃.

Reaction conditions: This reaction requires high temperature and pressure to occur. Additionally, the presence of a suitable catalyst is necessary to accelerate the reaction rate.

Reaction process: Iron reacts with iron(II,III) oxide to create iron(III) oxide. This process is an oxidation-reduction reaction, in which iron is oxidized from the oxidation state of 0 to +3, while iron in Fe₃O₄ is reduced from the oxidation state of +3 to +2.

Observed phenomenon: When the reaction occurs, we can observe color changes of the reacting substances. Specifically, Fe₃O₄ is black and turns into red-brown Fe₂O₃ after the reaction.