What is the molar mass of any substance defined as?
The mass of one mole of the substance.
In chemistry, the molar mass is a physical property defined as the mass of a given substance divided by the amount of substance. The base SI unit for molar mass is kg/mol. The most practical chemical molar mass used is g/mol because kilogram quantities are not usually used in chemical experiments.
Some example calculations are here: https://www.thoughtco.com/molar-mass-example-problem-609569
The “mole” (mol) is