What is the molar volume of a gas?

The molar volume of a gas is defined as the volume occupied by one mole of that gas at a specified temperature and pressure, often taken to be 0 degrees Celsius and 1 atmosphere of pressure (standard temperature and pressure, STP). This definition is rooted in the ideal gas law, which states that under ideal conditions, gases will occupy the same volume per mole regardless of their chemical identity. At standard temperature and pressure, the molar volume of an ideal gas is approximately 22.4 liters. This concept is fundamental in chemistry because it allows chemists to calculate the amounts of reactants and products in gas reactions using stoichiometry.

In contrast to this correct interpretation, the other options describe different aspects of gases but do not accurately define molar volume. One option mentions the volume occupied by two moles, which would not be a proper characterization of molar volume, as the term specifically refers to one mole. Another option refers to the total volume of gas in a container, which could vary depending on the number of moles present, not defining the volume per mole. Lastly, while the definition at standard temperature and pressure may seem close, the term "molar volume" itself is not limited to just those conditions and can apply