What is molar mass?

Molar mass is defined as the mass of one mole of a substance, typically expressed in grams per mole (g/mol). This concept is rooted in the relationship between the mass of a substance and the number of particles it contains, as established by Avogadro's number, which states that one mole of any substance contains approximately (6.022 \times 10^{23}) entities (atoms, molecules, etc.).

To determine the molar mass of a compound, one would sum the atomic masses of all the atoms present in one molecule of the compound using the periodic table. For example, the molar mass of water (H2O) is calculated by summing the molar masses of its constituent elements: 2 hydrogen atoms (about 1 g/mol each) and 1 oxygen atom (about 16 g/mol), leading to a molar mass of about 18 g/mol.

Understanding molar mass is crucial for stoichiometry and chemical reactions because it allows chemists to convert between the mass of a substance and the number of moles, which is essential when balancing equations and calculating yields.