The mass of nitrogen gas (N2) can be determined by its molecular weight. The atomic mass of nitrogen (N) is approximately 14.01 g/mol. Since nitrogen gas exists as diatomic molecules (N2), we need to multiply the atomic mass by 2.
Therefore, the molar mass of N2 is:
14.01 g/mol × 2 = 28.02 g/mol
This means that one mole of N2 weighs about 28.02 grams. In practical terms, if you have a sample of nitrogen gas at standard temperature and pressure (STP), one cubic meter of this gas will contain about 1.25 grams of nitrogen.