Question

Lysine, an essential amino acid in the human body, contains C,H,O and N only. In an experiment, the complete combustion of 2.175 g lysine gave 3.94 g of CO2 and 1.89 g of H2O. In another reaction, the nitrogen content of 1.873 g of lysine is quantitatively converted to 0.436 g of NH3.
i) Calculate the empirical formula of lysine.