Final answer:
The volume of one mole of any ideal gas at STP is 22.4 liters, a fact that is independent of the molar mass of the gas. Gas density, on the other hand, is dependent on molar mass since all gases occupy the same molar volume under these conditions. Therefore, the density calculation uses the gas's molar mass divided by a constant molar volume.
Step-by-step explanation:
The volume occupied by one mole of a gas at standard temperature and pressure (STP) is 22.4 liters. This is based on Avogadro's Law, which states that the volume of a gas is directly proportional to the number of moles of the gas, assuming the temperature and pressure are held constant. Regardless of the gas's molar mass, one mole of any ideal gas will occupy the same volume at STP.
The notion that the volume occupied by one mole of a gas is dependent on the molar mass of the gas is actually a misconception. Instead, the density of a gas is dependent on its molar mass. Since the volume is constant for one mole of any gas at STP, the density can be calculated using the formula density (p) = molar mass (M) / molar volume (V).
Given this, the density of a gas with a higher molar mass will be greater than that of a gas with a lower molar mass because they both occupy the same molar volume at STP.