The molar volume, symbol V_{m}, is the volume that one mole of an ideal gas occupies at a given temperature and pressure.
An ideal gas obeys the ideal gas law,
If n =1 mol, the molar volume, V_{m}, can be calculated by rearranging the ideal gas equation
where,
V_{m} = molar volume of an ideal gas, L mol^{-1}or dm^{3}/ mol
R is the ideal gas constant, 8.314 472 J mol^{–1} K^{–1}
T = temperature, Kelvin, K
P = pressure, kilopascals, kPa
The standard conditions for temperature and pressure set by the International Union of Pure and Applied Chemistry or IUPAC are 0 °C (273.15 K, 32 °F) and 100 kPa. (1 atm)
The molar volume of and ideal gas under standard conditions is 22.71 L
Other molar volumes can be calculated from the ideal gas equation and are shown in the Molar Volume table below
Molar Volume, L mol^{-1} or dm^{3}/ mol
Temperature |
100 kPa pressure (1 atm) |
101.3 kPa pressure (1 atm) |
0 °C, 32 °F |
22.71 (Standard conditions, IUPAC) |
22.41 |
20 °C |
24.37 |
24.06 |
25 °C |
24.79 |
24.47 |