Question

When $0.273$ g of $Mg$ is heated strongly in a nitrogen $\left(N_2\right)$ atmosphere, a chemical reaction occurs. The product of the reaction weighs $0.378$ g. Empirical formula of the compound is :

• A. $MgN$
• B. $M{g}_3{N}_2$
• C. $Mg{N}_2$
• D. $M{g}_{2}N$

Answer 1

The correct option is B $M{g}_3{N}_2$

Weight of Mg $=0.273g$
Weight of product formed with nitrogen $=0.378g$
Weight of nitrogen reacted $=0.105g$

Element	Amount		Mole	Ratio	Whole number
Mg	0.273 g		0.011	1.5	3
N	0.105		0.0075	1.0	2

Thus, the empirical formula of the compound is $M{g}_3{N}_2$.