A mole is defined as the amount of a substance that contains exactly 6.02214076 X1023 elementary entities of the given substance. A mole of a substance is referred to the mass of a substance containing the same number of fundamental units as there are atoms in exactly 12.000 g of 12C.
Why is mole used?
The term mole is used to represent quantities that cannot be measured with units like grams or milligrams. Therefore, a mole measures the number of atoms, ions or molecules.
Number of moles in a substance
he number of moles of a substance in a given pure sample can be represented by the following formula:
n = N/NA
n is the number of moles of the substance (or elementary entity), N is the total number of elementary entities in the sample,
NA is the Avogadro constant. The number 6.02214076 X1023 is popularly known as the Avogadro constant.