Number of Gas Molecules per Volume

A calculator for the number of gas molecules of an ideal gas under standard conditions for a given volume. One cubic meter of an ideal gas at a temperature of 0 degrees Celsius and a pressure of 1013.25 millibars contains 2.686780111 * 10²⁵ gas molecules, or, in the case of noble gases, gas atoms. This value is the Loschmidt constant, named after the Austrian physicist and chemist Josef Loschmidt, who discovered this value in 1865.
Under different conditions, the number of molecules changes of course. Therefore, the value of molecules per cubic meter can be adjusted for a case in which it can be determined for specific conditions. For standard conditions, leave it unchanged. Please enter the volume or the number of molecules in it to calculate the other value.

Example: 12 liters (volume 12 l) of an ideal gas contain 3.224136133 * 10²³ molecules under standard conditions.

In fact, no gas existing in nature is an ideal gas, but some are very close, particularly hydrogen, helium, and the other noble gases. All gases behave more like ideal gases the lower the pressure and the higher the temperature. For non-ideal gases, the number of molecules per volume is higher for a compressibility factor Z < 1 and lower for a compressibility factor Z > 1. The compressibility factor Z depends on pressure and temperature; for nitrogen, it is less than 1 over a wide range, for hydrogen, it is close to 1, and for high pressure, it is above that.
For the physical properties of ideal gases and their calculation, see the ideal gas law. A similar constant to the Loschmidt constant is the much more well-known Avogadro constant. This does not refer to volume, but to mass; for calculations using this, see molar mass.