2 N₂ (g) + O₂ (g) ⇌ 2 N₂O
When nitrogen and oxygen reacts nitrous oxide is formed.
Molar mass of N = 14.0067 g/mol and N₂ = 28.0134
molar mass of O = 15.9998 g/mol
molar mass of N₂O =28.0134 + 15.9998 = 44.0132 g/mol
Now we first find the percent composition of N in N2O.
(14.0067(2)/44.0128)100 = 63.65% of N
use the percent to find the mass of N in 74.0g of N₂O
63.65% = 0.6365
74.0g (.6365) = 47.10g of N
Now convert the g to mol
47.10g (1 mol/14.0067g) = 3.36 mol N