Question

Write a balanced chemical reaction for the formation of rust.

Answer 1

1. Corrosion: Wasting away of material layer by layer due to the presence of air and moisture is called corrosion.
2. When iron corrode it is called rusting.
3. Rusting is the slow oxidation of Iron by atmospheric Oxygen in the presence of Water or moisture.
4. When Iron$\left(\mathrm{Fe}\right)$ combines with Oxygen $\left({\mathrm{O}}_2\right)$ and Water$\left({\mathrm{H}}_2\mathrm{O}\right)$, it results in the formation of rust.
5. The balanced chemical reaction for the formation of rust can be given as: $\underset{\mathbf{\left(}\mathbf{Iron}\mathbf{\right)}}{\underbrace{\mathbf{4}\mathbf{Fe}\mathbf{}\mathbf{\left(}\mathbf{s}\mathbf{\right)}}}\mathbf{}\mathbf{+}\mathbf{}\underset{\mathbf{\left(}\mathbf{Oxygen}\mathbf{\right)}}{\underbrace{\mathbf{3}{\mathbf{O}}_{\mathbf{2}}\mathbf{}\mathbf{\left(}\mathbf{g}\mathbf{\right)}}}\mathbf{}\mathbf{+}\underset{\mathbf{\left(}\mathbf{Water}\mathbf{\right)}\mathbf{}}{\underbrace{\mathbf{}\mathbf{x}\mathbf{.}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{}\mathbf{\left(}\mathbf{l}\mathbf{\right)}\mathbf{}}}\mathbf{\to }\underset{\mathbf{(}\mathbf{Rust}\mathbf{/}\mathbf{Hydrated}\mathbf{}\mathbf{ferric}\mathbf{}\mathbf{oxide}\mathbf{)}}{\underbrace{\mathbf{2}{\mathbf{Fe}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{3}}\mathbf{.}{\mathbf{xH}}_{\mathbf{2}}\mathbf{O}\mathbf{}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}}}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}\mathbf{}$
6. To prevent from rusting we could take following measures like painting, coating, galvanizing, tinning, electroplating etc.
7. Rusting causes loss of metals from the surface, it also changes the physical appearance of the metal, due to rusting machines, buildings or bridges loses their efficiency with time and due to this reason life span of metallic objects decreases.