Final answer:
At STP, defined as 0°C and 1 atm pressure, one mole of any gas occupies 22.4 L. This is known as the standard molar volume and is based on Avogadro's hypothesis and the ideal gas law.
Step-by-step explanation:
At Standard Temperature and Pressure (STP), which is defined as 0°C (273.15 K) and 1 atmosphere pressure, one mole of any gas occupies a volume of 22.4 L. This uniform volume is known as the standard molar volume and applies to ideal gases. The concept is based on Avogadro's hypothesis, which states that equal volumes of gases at the same temperature and pressure contain the same number of particles (molecules or moles).
Using the ideal gas law, which is given by the equation (PV = nRT), where 'P' is pressure, 'V' is volume, 'n' is the amount of substance in moles, 'R' is the ideal gas constant, and 'T' is temperature, we can determine that at STP, the volume (V) for one mole of gas, when 'P' is 1 atm and 'T' is 273 K, and using the value of 'R' as 0.0821 L⋅atm/K⋅mol, is indeed 22.4 L.
It is important to note that this applies to ideal gases under those specific conditions of STP. For real gases, or if the conditions deviate from STP, corrections may need to be made, and the volume may be different.