Final answer:
The question deals with the chemical reaction between iron and oxygen leading to the creation of iron oxides such as rust. This involves oxidation-reduction processes where iron is oxidized and oxygen is reduced by electron transfer.
Step-by-step explanation:
The student's question is about the chemical reaction that occurs between iron (Fe) and oxygen (O₂), which is a fundamental concept in the area of Chemistry. Specifically, this is related to redox reactions, where one substance is oxidized and the other is reduced. Looking at the equation 2 Fe²⁺ (aq) + O₂(g) + 4H⁺ (aq) → 2 Fe³⁺ (aq) + 2H₂O(l), we can see that oxygen binds with iron (forming iron (III) ions) and is reduced by accepting electrons while iron is oxidized by losing electrons. This concept also applies when solid iron objects like nails react with oxygen in humid air, leading to the formation of rust, which is essentially hydrated iron (III) oxide.
Moreover, the balanced chemical equation 4 Fe²⁺ (aq) + O₂(g) + (4 +2 x)H₂O(l) → 2 Fe₂O₃ · xH₂O(s) + 8 H⁺ (aq) demonstrates the variable nature of water molecules in the formula for rust. It's important to understand that such reactions are governed by the principles of oxidation and reduction, which are integral to the field of Chemistry. Here, iron's oxidation state changes with oxygen's presence, signaling a transfer of electrons in the reaction.