Question

Chemically rust is ____.

Answer 1

1. When exposed to the environment, the slow process of degradation of metals undergoes chemical and electrochemical reaction processes due to the presence of moisture and other elements is said to be corrosion.
2. Rusting is a part of corrosion, where the material undergoes chemical reactions and produces an oxide layer film over it.
3. In the presence of moisture and oxygen available in the air, iron combines to form a brown coating called rust (ferric oxide).
4. It is otherwise called hydrated ferric oxide. The chemical formula of rust is ${\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O}$.
5. A balanced chemical equation is:

$$\begin{gathered} \mathrm{Fe}\left(\mathrm{s}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\to {\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O} \\ (\mathrm{oxygen}\mathrm{and}\mathrm{moisture}(\mathrm{Hydrated} \\ \mathrm{from}\mathrm{air})\mathrm{ferric}\mathrm{oxide}) \end{gathered}$$

Hence, chemically rust is ${\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O}$.