Answer:
28 g/mol
Explanation:
1 mole of a substance contains a number of molecules equal to Avogadro number:
[tex]N_A=6.022\cdot 10^{23}[/tex]
This means that 1 mole of nitrogen contains [tex]N_A[/tex] molecules.
1 molecule of nitrogen consists of 2 atoms of nitrogen, each of them with an atomic mass of 14 atomic mass units; so, the total mass of 1 molecule of nitrogen is:
[tex]m=2\cdot 14\cdot m_p =2\cdot 14 \cdot (1.66\cdot 10^{-27} kg)=4.65\cdot 10^{-26} kg[/tex]
where [tex]m_p[/tex] is the mass of one proton.
Therefore, the total number of molecules in 1 mole of nitrogen is equal to the mass of 1 molecule times the total number of molecules:
[tex]M=mN_A=(4.65\cdot 10^{-26})(6.022\cdot 10^{23})=0.028 kg[/tex]
So, 28 g/mol
