Question

How much mass would a mole of nitrogen molecules contain? Recall that nitrogen is diatomic. g/mol

Answer 1

Answer:

28 g/mol

Explanation:

1 mole of a substance contains a number of molecules equal to Avogadro number:

$N_A=6.022\cdot 10^{23}$

This means that 1 mole of nitrogen contains $N_A$ 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:

$m=2\cdot 14\cdot m_p =2\cdot 14 \cdot (1.66\cdot 10^{-27} kg)=4.65\cdot 10^{-26} kg$

where $m_p$ 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:

$M=mN_A=(4.65\cdot 10^{-26})(6.022\cdot 10^{23})=0.028 kg$

So, 28 g/mol