Why Is Rusting Of Iron Said To Be An Electro Chemical Reaction?
Corrosion of steel and iron is also known as rusting. Iron compounds, when exposed to water and oxygen corrode and form rust on the surface. Rust is composed of iron oxides and hydroxides. In its natural state, iron occurs as an ore called haematite or iron oxide. Metallic iron tends to revert back to iron oxide when it is exposed to air and water. The process of rusting gives off energy. There are three basic stages to rusting. Iron ions are formed on the metal; hydroxide ions are formed as well; with the addition of oxygen they react together and form rust. This is an electro chemical process. The ions released by contact with water travel to the edges of the droplet. Since there is more dissolved oxygen at the edges of the droplets the electrons reduce it to hydroxide ions. The iron ions react with hydroxide ions and the dissolved oxygen. This results in iron oxide or rust.
