The Mole and Avogadro’s Constant
The mole is the SI unit of the amount of substance. One mole of a substance is equal to 6.02214179 × 10 23 units of that substance. This number, 6.022 × 10²³, is known as Avogadro’s constant. The mole concept can be applied to convert mass and number of particles. One mole of atoms of any element will contain a mass equal to the relative atomic mass expressed in grams. The mass of a mole of a substance is referred to as the Molar Mass of that substance. The molar mass is applied in the conversion of grams to moles in chemistry. The relationship between molar mass and atomic mass is derived from the conversion factor of one mole of substance/ molar mass of the substance.
The concept of the mole is also applied in determining the chemical composition of compounds. For example, consider methane CH4. The molecular formula indicates that one mole of methane contains one mole of carbon and four moles of Hydrogen. The mole concept is used in the application of ratios. For example,
1mol C + 2mol O = 1 mol CO2
In this chemical reaction, C and O’s moles describe the number of atoms that reacted to form 1mol of CO2.
Ideally, the mole concept can be challenging to visualize because Avogadro’s constant is extremely large. The idea of the mole is analogous to other quantities, like dozens and pairs. For instance, a pair means two things of a kind, while a dozen means twelve things of a kind. The mole also means 6.02214179×1023 of something.
1 mole=6.02214179×10 23 particles
1 pair of shoes =2 shoes
1 dozen eggs =12 eggs