Question

a compared of magnesium nitric contains 72% of magnesium and 28% of nitrogen. what is the empirical formula of magnesium nitric.

and the answer is Mg 3 N 2

how to do the solution. ​

Answer 1

The empirical formula : Mg₃N₂

Further explanation  

The empirical formula is the smallest comparison of atoms of compound =mole ratio of the components

The principle of determining empirical formula

• Determine the mass ratio of the constituent elements of the compound.  

• Determine the mole ratio by dividing the percentage by the atomic mass

The empirical formula :

mol ratio Mg : N ⇒

$\tt =\dfrac{72}{24~g/mol}\div \dfrac{28}{14~g/mol}\\\\=3\div 2\rightarrow Mg_3N_2$