Question

A compound of carbon, hydrogen and nitrogen contains these elements in the ratio 9 : 1 : 3.5. Calculate the empirical formula. If its molecular mass is 108, what is the molecular formula?

Answer 1

The empirical formula =C₃H₄N

Empirical formula mass=(3×12)+(4×1)+14=54

n = Mol.Mass/Emp.mass 

=108/54

=2

Thus,molecular formula of the compound =2×Empirical formula

⇒2×C₃H₄N

⇒C₆H₈N₂