How is molar mass defined?

Molar mass is defined as the mass of one mole of a pure substance, which corresponds to the quantity of entities (atoms, molecules, or formula units) present in one mole based on Avogadro's number (approximately (6.022 \times 10^{23})). The unit of molar mass is grams per mole (g/mol), and it is a critical concept in chemistry, particularly in stoichiometry, as it allows chemists to convert between the mass of a substance and the amount in moles.

The definition of molar mass reflects the average mass of the atoms in a mole of the element or compound, directly connected to the atomic or molecular weights found on the periodic table. By knowing the molar mass, one can determine how many grams of a substance are needed to have a specific number of moles, making it essential for calculations involving reactions and conversions in chemistry.

The other definitions do not accurately encompass the concept of molar mass. The mass of one atom pertains to atomic mass, which is relevant for individual elements but does not relate to moles. The combined mass of molecules could suggest consideration of multiple entities, but it does not encapsulate the standardized measurement provided by molar mass. The weight