Let the total mass of the compound is 100 g.
Mass of N = 63.65 % = 63.65 g
Mass of O = 36.35 % = 36.35 g
Molar mass of N = 14.01 g/mol
Molar mass of O = 16.00 g/mol
Number of moles (mol) = mass (g) / molar mass(g/mol)
Number of Moles of N = 63.65 g / 14.01 g/mol = 4.54 mol
Number of Moles of O = 36.35 g / 16.00 g/mol = 2.27 mol
Divide the Number of moles of each element with the lowest number of moles, here lowest number of moles is 2.27 .
Dividing number of the moles of each element by lowest number of moles to get the mole ratio between elements.
N = 4.54 mol / 2.27 mol = 2
O = 2.27 mol / 2.27 mol = 1
So, Empirical formula = N₂O₁ = N₂O