Pratik heated 11.2 grams of element ‘M’ (atomic weight 56) with 4.8 grams of element ‘N’ (atomic weight 16) to form a compound. Find the empirical formula of…

Gram atom = $\frac{\text{Mass of element}}{\text{Atomic mass}}$

∴ g atom of M = $\frac{11.2}{56}$ = 0.2

and, g atom of N = $\frac{4.8}{16}$ = 0.3

simple ratio of gram-atoms of M to gram-atoms of N

= $\frac{0.2}{0.3}$ = $\frac{2}{3}$ = M : N

So, the formula is M₂N₃