Molar volume at STP refers to the volume occupied by one mole of an ideal gas under standard temperature and pressure (STP) conditions.
- Standard Temperature (ST) = 0 °C or 273 K
- Standard Pressure (SP) = 1 atm (101.3 kPa)
At these conditions, 1 mole of any ideal gas occupies 22.4 liters.
This means, whether it is oxygen, nitrogen, hydrogen, or carbon dioxide, as long as the gas behaves ideally, 1 mole always has a volume of 22.4 L at STP.
This concept is very useful because it lets chemists easily convert between moles of gas and volume in liters during calculations.