# What is a Mole?

The term ‘molar” was derived from the Latin *moles *meaning a large mass. The concept of mole was first introduced by August Wilhelm Hofman the German chemist into the chemistry. Therefore, mole is the unit of measurement in the International System of Units (SI) for amount of substance (Jensen, 2004). The relationship between mole and Avogadro’s number i.e. 6.0224 * 10^{23} came as result of equating 1 Mole to the value of Avogadro’s number. This means that when a matter is described to have 1 mole in quantity, the matter under consideration constitutes exactly 6.0224 * 10^{23} number of particles such as electrons, ions, molecules, atoms or any other elementary entities.

The concept of mole was needed because it was very challenging to carry out calculations when dealing with very small particles in the size of molecules and atoms since they are present in a very large number. The number of elementary particles in a small sample of a chemical compound or an element exists in the higher order of 10 (Onishi, 2004). As a result, the introduction of mole made it simpler to do calculations when dealing with small size particles such as atoms and molecules. Also, it was necessary to define a mole in reference to an element that contain as many elementary entities as there are in exactly 12 gm of Carbon – 12. Therefore, Avogadro’s number is the number of atoms in 12 gm of Carbon – 12.

The definition of mole depends on its application; the mole can be defined in terms of particles, volume and mass (Mihir, 2017). This means that the mole concept can be used to carry out various other calculations in the field of chemistry.