The molar mass of N2 is 28.0134 g/mol. Obtain this by adding the molar masses of the two nitrogen atoms in the molecule (14.0067 g/mol each). Since N2 is a known substance, the number of moles is unnecessary to find its molar mass.
For a mixture of gases, use the ideal gas law formula to find the number of moles and the weighted mass:
molar mass = mass / number of moles Read more