MgThe empirical formula is calculated as follows
fin the moles of each element
moles = % composition/ molar mass
magnesium(Mg) = 72.2/24 = 3moles
Nitrogen(N) = 27.8/14 = 1.986 moles
find the moles ration by dividing each mole by the smallest mole ( 1.986 moles)
that is
magnesium)Mg) = 3/1.986 = 1.5
Nitrogen (N)= 1.986/1.986 =1
multiply both the mole ratio to remove the decimal
magnesium (Mg) = 1.5 x2 = 3
nitrogen (N)= 1 x2 =2
therefore the empirical formula = Mg3N2