The formula of ammonium nitrate is
NH4NO3
The molar mass of NH4NO3
(=N2H4O3)is = (2xAt.mass of N ) +
(4xAt.mass of H ) + (3xAt.mass of O)
                                                           Â
= (2x14) + (4x1) + (3x16)
                                                           Â
= 80 g/mol
Therefore the molar mass of NH4NO3 is 80
g/mol