Basics of Mole Concept

In chemistry, substances consist of large particles. As a result, the best way of expressing these particles is through a unit called a “mole." Therefore, a mole represents the amount of these particles in chemical substances such as chemical elements and molecules.

For instance, a specific gram of a chemical element can contain many atoms. A mole is described as the quantity of a chemical substance with 6.02214076*10²³ discrete entities as the number of atoms present in ¹²C, which weighs 12g. This number represents Avogadro's constant (N_A). Particles represented in a mole encompass molecules, polyatomic/monoatomic ions, atoms, electrons, etcetera. 

The Avogadro's constant is considered "per mole" in chemistry and rounded off to 6.022*10²³/mol. For this reason, one mole of a specific element comprises the same amount of atoms as represented in one mole of another element. However, a mole of distinctive elements contains different masses since specific atoms of these elements are unlike, leading to molar mass.

Molar mass refers to the mass (always in grams) of a mole of a specific chemical substance. It is expressed in g/mole (grams per mole). The atomic unit mass and mole are based on ¹²C.

Therefore, the molar mass of a particular chemical substance is mathematically the same as its formula or atomic weight in amu. Based on the amu, one 12C atom contains 12amu, representing its atomic mass. On the other hand, the mole’s definition indicates that 12g of carbon-12 comprises a mole of C-12 atoms, representing its molar mass (12g/mol). This relationship applies to all elements because they use the same reference substance (¹²C).