Question

Rust is hydrated

• A. alumininum oxide
• B. copper oxide
• C. iron oxide
• D. silica

Answer 1

The correct option is C

iron oxide

C

• The slow deterioration of the surface of any metal by its reaction with air, moisture or any chemical substance is termed as corrosion.
• Corrosion in the case of Iron $\left(\mathrm{Fe}\right)$ is termed as rusting.
• Iron $\left(\mathrm{Fe}\right)$ undergoes reaction with Oxygen gas $\left({\mathrm{O}}_2\right)$ in air and Water $\left({\mathrm{H}}_2\mathrm{O}\right)$ to form hydrated Iron(III) oxide $({\mathrm{Fe}}_2{\mathrm{O}}_3·{\mathrm{H}}_2\mathrm{O})$. This brown colored hydrated Iron(III) oxide is termed as rust.

$4\mathrm{Fe}\left(\mathrm{s}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3·{\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)$

Hence, option C is correct. Rust is hydrated iron oxide.