Question

Rusting of iron is faster in saline water than ordinary water. Why?

Answer 1

1. Rusting is a form of oxidation. Rust is formed when iron combines with water and oxygen to generate hydrated Iron(III) oxide.
2. When iron and steel come into touch with water and oxygen (all of which are required for rusting to occur), this accelerates the speed of rusting process.
3. Rusting is catalyzed by ${\mathrm{H}}^{+}$ ions produced due to salt hydrolysis which is present in high amounts in saline water catalzsing the process of rusting.
4. This is the reason why rusting of iron is faster in saline water than ordinary water.