Difference Between Rusting and Corrosion


Rusting and corrosion both are oxidation reactions. Corrosion occurs over a wide range of objects while rusting is limited as it occurs only on iron. We can say rusting is a type of corrosion or most common example of corrosion as rusting of iron objects is very commonly found.


What is Rusting? 

Rusting is oxidation of iron or iron objects. It takes place in the presence of air and moisture. It is a slow process. Due to rusting, rust is formed on iron objects. It is a red-orange colored iron oxide which is formed by the oxidation of iron in presence of oxygen and moisture or water.

Reactions involved can be written as follows –

4Fe + 3O2 🡪 2Fe2O3

2Fe2O3 + xH2O 🡪 Fe2O3.xH2O

                                 Rust 


What is Corrosion? 

Corrosion is oxidation of metals and non-metals which results in destruction and unintentional degradation of a materials by its environment. It forms oxides, hydroxides and sulfides of the elements present in the material. 

Difference Between Corrosion and Rusting 

Corrosion 

Rusting 

Corrosion is the process of deterioration of metals and non-metals by oxidation. 

Rusting is oxidation of iron (or steel) in presence of air and moisture. 

Corrosion can occur on both metals and non-metals. It may occur on skin and wood as well. 

Rusting occurs on metals only such as iron and steel.

Corrosion includes rusting. 

Rusting is a type of corrosion. 

It requires exposure of air or chemicals on surface. 

It requires air and moisture both. 

It may require corrosive chemicals such as HCl, H2SO4 and other strong acids and bases. 

It doesn’t require any chemicals. 

The compound (or a layer) formed by corrosion can of different colors such as blue, green etc. 

Rusting forms rust which is red orange in color. 


What is Rancidity?

Generally, students get confused between corrosion and rancidity. Rancidity is different from corrosion although it is also an oxidation reaction. Rancidity is oxidation of fats and oils present in food materials due to which smell and taste of the food material changes.

We can prevent it by adding antioxidants and keeping food in airtight containers.


Prevention from Corrosion, Rusting and Rancidity 

  • Prevention from Corrosion – Following methods can be used to prevent corrosion –

  • By putting barrier coatings such as paint, plastics etc. on the surface of the materials. 

  • Hot dip galvanization process can be used. 

  • We can form alloys to prevent them from corrosion. 

  • Cathodic protection can be used. 

  • Prevention from Rusting – Following methods can be used to prevent rusting –

  • Keep steel and iron objects clean and dry and away from moisture, air. 

  • By applying a protective coating.

  • By using alloys of iron instead of pure iron. 

  • By galvanization. 

  • By forming a layer of ferric oxide using potassium nitrate and sodium hydroxide. 

  • Prevention from Rancidity – Following methods can be used to prevent rancidity –

  • By using inert gases in packaging. 

  • By using oxygen scavengers. 

  • By refrigeration of food materials. 

  • By storing food materials in dark place. 

  • By using airtight containers. 

  • By using vacuum packaging.

  • By using anti-oxidants.

We hope it will help you to understand the difference between corrosion and rancidity. Still if you have any doubt don’t hesitate to join doubt class on Vedantu. You can also register yourself on Vedantu or download Vedantu learning app for Class 6-10, IITJEE and NEET to get access to free PDFs of NCERT Solutions, Study materials and much more.