Kilogram per Mole

The unit $\textit{}$, symbol $kg/mol$, is the base SI unit for molar mass. In chemistry, the molar mass $M$ is defined as the mass of a given substance (chemical element or chemical compound) divided by its amount of substance. It is a physical property of a given substance. However, for historical reasons, molar masses are almost always expressed in $g/mol$. As an example, the molar mass of water is approximately: $18.01528(33) \; g/mol$.