A compound contains 28% of nitrogen and 72% of a metal by weight. 3 atoms of the metal combine with 2 atoms of nitrogen. Find the atomic weight of the metal.

A compound contains 28% of nitrogen and 72% of a metal by weight. 3 at

1.	A compound contains 28% of nitrogen and 72% of a metal by weight. 3 atoms of the metal combine with 2 atoms of nitrogen. Find the atomic weight of the metal.
Answer» Solution :SUPPOSE, the symbol of the GIVEN metal is M. SINCE, 3 atoms of the metal COMBINE with 2 atoms of nitrogen, the formula of the compound should be `M_3N_2`. Suppose, the atomic mass of M is x. The MOLECULAR mass of `M_(3)N_(2) = (3 xx x) + (2 xx 14.01) = 3x + 28.02` The percentage of nitrogen in `M_(3)N_(2) = (28.02)/(3x + 28.02)xx 100` Since, the given compound contains 28% of nitrogen, we have `=(28.02 xx 100)/(3x + 28.02) = 28` Which gives `x=24.02` Hence, the atomic mass (weight) of the metal is 24.02 amu.