Question

Which number completes the chemical equation showing the process of rusting:

4Fe + 3O_2 -> ___Fe_2O_3
a) 1
b) 2
c) 4
d) 12

Answer 1

The correct number that completes the chemical equation showing the process of rusting is 2: 4Fe + 3O2 -> 2Fe2O3.

Step-by-step explanation:

The number that completes the chemical equation for the process of rusting is 2.

The balanced chemical equation for the rusting of iron (Fe) when it reacts with oxygen (O2) to form iron(III) oxide (Fe2O3) can be represented as 4Fe + 3O2 -> 2Fe2O3. In this reaction, iron is oxidized to Fe2+ ions at an anodic site, while oxygen is reduced to water at a different site on the surface of the iron. Rust forms as Fe2+ ions react further with atmospheric oxygen in humid conditions, resulting in hydrated iron(III) oxide (rust).