Molar volume
Molar volume is the volume occupied by one mole of a substance under specified conditions of temperature and pressure.
Ideal gas law: An equation relating a gas’s pressure, volume, temperature, and amount of substance. For an ideal gas, molar volume follows from pressure and temperature in this equation.
Molar volume of a gas: The volume occupied by one mole of a gas at specified temperature and pressure. Gas calculations often use this condition-dependent form of molar volume.
Mole (unit): The SI unit for amount of substance, defined by an exact number of specified entities. Molar volume uses the mole as its unit of amount.
Specific volume: The volume of a substance per unit mass. Unlike molar volume, specific volume divides volume by mass rather than amount.
Density: Mass per unit volume of a substance. Dividing molar mass by density yields molar volume for a uniform substance.
Standard molar volume: The molar volume of a gas at a specified standard temperature and pressure. Its numerical value depends on which standard conditions are chosen.
Amount of substance: A quantity measuring how many specified elementary entities a sample contains. Molar volume is defined by dividing volume by amount of substance.
Molar mass: The mass of one mole of a substance, usually expressed in grams per mole. It pairs with molar volume but measures mass per mole, not volume per mole.
Avogadro constant: The number of specified elementary entities in one mole, exactly 6.02214076 × 10²³. It connects a mole’s count of particles to the amount used in molar-volume calculations.
Partial molar volume: The change in a mixture’s total volume when an infinitesimal amount of one component is added. It extends molar-volume reasoning to components in mixtures, where volumes need not add ideally.