V_m = 22.414 L/mol (ideal gas at STP); V_m = M/ρ (liquids/solids)
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Quick Reference
Formula / Notation
V_m = 22.414 L/mol (ideal gas at STP); V_m = M/ρ (liquids/solids)
Also Known As
Molar volume, V_m, specific molar volume, 22.4 L/mol (STP approximation)
What is Molar Volume?
The volume occupied by one mole of a substance. At STP (0°C, 1 atm), one mole of an ideal gas occupies 22.4 L. At standard conditions (25°C, 1 bar), the molar volume is 24.8 L. Molar volume of solids and liquids varies considerably from substance to substance.
Formula & Notation
V_m = 22.414 L/mol (ideal gas at STP); V_m = M/ρ (liquids/solids)
Other Names / Synonyms: Molar volume, V_m, specific molar volume, 22.4 L/mol (STP approximation)
Properties & Characteristics
Molar volume (V_m) is the volume occupied by one mole of a substance. For an ideal gas at STP (0°C, 1 atm): V_m = RT/P = 22.414 L/mol. At SATP (25°C, 1 bar): V_m = 24.79 L/mol. For liquids and solids, molar volume = molar mass / density. Molar volumes of liquids and solids are much smaller than gases (water: 18.02 mL/mol). Molar volume is an intensive property and provides insight into intermolecular interactions.
Uses & Applications
Molar volume is used in: gas law calculations, converting between moles and volume of gases, comparing packing efficiency of solids (partial molar volumes in solutions), designing gas storage systems, and in electrochemistry (volume changes during electrode reactions).
Safety Information
No direct safety concern for the concept. The large molar volume of gases (>22 L/mol) compared to liquids (<1 L/mol) means that small volumes of liquid can produce very large volumes of gas — relevant to understanding the hazard of rapid liquid-to-gas transitions (liquid nitrogen spills, aerosol can explosions).
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
TermMolar Volume
FormulaV_m = 22.414 L/mol (ideal gas at STP); V_m = M/ρ (liquids/solids)
SynonymsMolar volume, V_m, specific molar volume, 22.4 L/mol (STP approximation)
Frequently Asked Questions
The volume occupied by one mole of a substance. At STP (0°C, 1 atm), one mole of an ideal gas occupies 22.4 L. At standard conditions (25°C, 1 bar), the molar volume is 24.8 L. Molar volume of solids and liquids varies considerably from substance to substance.
Molar volume is used in: gas law calculations, converting between moles and volume of gases, comparing packing efficiency of solids (partial molar volumes in solutions), designing gas storage systems, and in electrochemistry (volume changes during electrode reactions).
No direct safety concern for the concept. The large molar volume of gases (>22 L/mol) compared to liquids (
The formula or notation for Molar Volume is: V_m = 22.414 L/mol (ideal gas at STP); V_m = M/ρ (liquids/solids)
Editorial standards: Chemical data is sourced from peer-reviewed literature,
CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA,
and IAEA. For educational purposes only — always consult official SDS documentation and qualified
professionals before handling chemicals.
