Molar volume The molar volume, symbol Vm, is the volume occupied by one mole of a substance (chemical element or chemical compound) at a given temperature and pressure. It is equal to the molar mass (M) divided by the mass density (?). [Wikipedia: https://en.wikipedia.org/wiki/Molar_volume] Chemistry New for ODM2 http://dbpedia.org/page/Molar_volume ODM2 Units Type Controlled Vocabulary ODM2 Working Group A vocabulary for describing the type of the Unit or the more general quantity that the Unit represents.