Moles and Molar Mass

Moles

A mole is a unit used in chemistry to express amounts of a chemical substance. It is defined as exactly 6.022x10^23 particles which can be atoms, molecules, or ions.
This particular number is known as Avogadro’s Number which is symbolised by Nₐ.
The mole is used in chemistry to determine amounts of a substance, it is comparable to measuring items by dozen (1 Moles = Avogadro’s number of particles).
One mole of any element or compound contains the same number of entities (atoms, molecules, or ions) as there are atoms in exactly 12 g of Carbon-12.

Molar mass of a substance is the mass in grams of one mole of that substance.
It is equal to the atomic, molecular or formula mass in atomic mass unit (amu), but expressed in grams.
One mole of carbon-12 atoms has exactly 12 grams of carbon and contains Nₐ atoms. This is used as a basis for other calculations involving molecular mass or moles.
The molar mass of an element or compound can be calculated by adding up the atomic masses of all the atoms in its chemical formula.
Molar mass is used in stoichiometry calculations which are calculations involving the mass of reactants and products in chemical reactions.

To calculate the number of moles from mass, we use the formula: Number of moles = Mass (grams) / Molar mass (grams/mole)
This formula allows for the conversion between mass and moles, provided the molar mass of a substance is known.
The molar mass of an element can be found on the periodic table, and to find the molar mass of a compound, you simply add up the molar mass of the all atoms in the compound’s formula.
You can also work out the number of particles (atoms, molecules, ions) if the number of moles is known by using Avogadro’s number; multiplying the number of moles by Avogadro’s number (Nₐ) gives the number of particles.