Solving the concentration of ammonium nitrate in mol dm^-3, we should first get the number of moles of ammonium nitrate.
The formula of ammonium nitrate is NH4NO3 and its molar mass is 80.052 g/mol. To solve for the number of moles, we divide the given mass (120g) with the molar mass.
Moles NH4NO3 = 120g NH4NO3/80.052 g/mol
Moles NH4NO3 = 1.49903 moles.
To get the concentration, we need to divide the number of moles with the volume of the solution. The required unit for volume is dm^-3.
1dm^3 = 1L
so the concentration would be:
=Moles NH4NO3/ volume of the solution
= 1.49903 moles/ 1dm^3
= 1.50 moles/dm^3
= 1.50 moles dm^-3