How many moles of nitrogen, N, are in 74.0 g of nitrous oxide, N2O?

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 N ₂O = 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 N ₂O

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