We find the number of moles by weight percentage:
The number of moles of Nitrogen = 87.4 g/ 14.0067 g/mol = 6.24 moles
Similarly, the number of moles of Hydrogen = 12.6 g / 1.008 g/mol = 12.5 moles
Now, we divide the no of moles to get a ratio : 12.5 / 6.24 = 2
Thus, the empirical formula from this ratio will be NH2 ( molar mass = 16.02 g/mol)
32.05/ 16.02 = 2
Thus, given mass of fuel is 32.05, so its empirical formula will be N2H4
