Question

How is corrosion different from rusting?

Answer 1

Hint: Rusting is a type of corrosion. Corrosion happens to a wide range of materials. But rusting is a process that is happening only to iron. Both involve chemical reactions. Both damage the metal.

Complete step by step answer:
Corrosion is the damage occurring to metals. Various oxides, hydroxides or sulphides form as a result of corrosion. The compound formed as a result of rusting is called rust.
Corrosion is a natural process which damages a metal. It occurs on metal surfaces. The surface that undergoes corrosion will be useless. All the properties of metal will be lost if it is corroded. Hence it is a dangerous problem for metals. Metal will be converted into corresponding oxides, hydroxides or sulphides. This happens because the oxides, hydroxides or sulphides are more stable than corresponding metal. Basically this is an oxidation reaction. Atom in zero oxidation state loses electrons and combines with oxygen. Corrosion can occur in air or water.
The most common type of corrosion is rusting of iron. Iron is a metal which has a vast majority of applications in our daily life. Iron reacts with atmospheric oxygen to form rust. The chemical name for rust is iron oxide and its chemical formula is $F{e_2}{O_3}.n{H_2}O$. The reaction happening while rusting of iron is,
$
  4Fe + 3{O_2} \to 2F{e_2}{O_3} \\
  2F{e_2}{O_3} + n{H_2}O \to F{e_2}{O_3}.n{H_2}O
 $
Pure iron metals combine with oxygen in the atmosphere and water vapour to form iron oxide. The number of water molecules is variable. It is a slow process. Rust is a red-orange coloured substance. Like all other forms of corrosion, rusting also causes damage to iron.

Note: Corrosion is a serious problem since it destroys the metals. Corrosion causes buildings and bridges to collapse, oil pipes to break, chemical plants to leak. Hence it is very important to take necessary precautions to prevent corrosion of all metals including iron.