Question

What is the chemical composition of rust?

Answer 1

• Rust is a chemical substance that is deposited on iron metal when the metal chemically reacts with moisture and air.

$$\begin{gathered} 4\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)+2{\mathrm{xH}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O}\left(\mathrm{s}\right) \\ \mathrm{iron}\mathrm{oxygen}\mathrm{water}\mathrm{hydrated}\mathrm{ferric}\mathrm{oxide} \\ \mathrm{Rust} \end{gathered}$$

• Rust is an iron oxide i.e. hydrated ferric oxide $({\mathrm{Fe}}_2{O}_3.{\mathrm{xH}}_{2}O)$.

So, The chemical formula of rust is ${\mathbf{Fe}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{3}}\mathbf{.}{\mathbf{xH}}_{\mathbf{2}}\mathbf{O}$ and the chemical composition is mainly iron and oxygen and also water(moisture).