Final answer:
The molecular formula for iron (III) oxide that forms as a result of the corrosion of iron is Fe2O3. The combination reaction for rust formation is 4 Fe2+ (aq) + O2(g) + (4 + 2x) H2O(l) → 2 Fe2O3 · xH2O(s) + 8 H+ (aq), where 'x' indicates the variable number of water molecules in the hydrated rust.
Step-by-step explanation:
The combination of iron and oxygen, which produces iron (III) oxide, is a part of the corrosion process and more specifically leads to the formation of rust.
The molecular formula for the iron (III) oxide that is formed in the rusting process and is often represented in chemistry as Fe2O3. The complete balanced chemical reaction, which does not need to mention the state of the products as per the question's requirement, would be:
4 Fe2+ (aq) + O2(g) + (4 + 2x) H2O(l) → 2 Fe2O3 · xH2O(s) + 8 H+ (aq)
This combination reaction shows iron ions reacting with oxygen and water to form hydrated iron(III) oxide, with a variable stoichiometry indicated by 'x' in the formula. The hydrated form means that molecules of water are incorporated into the crystal structure of the iron (III) oxide, which is characteristic of rust.