Question

A hydride of nitrogen contains $87.5$ percent by mass of nitrogen. Determine the empirical formula of this compound.

Answer 1

Step 1: Given that In hydride of nitrogen,

$\mathrm{N}\left(\mathrm{nitrogen}\right)=87.5\%$

$\mathrm{Hydrogen}\left(\mathrm{H}\right)$ $=100\%-87.5\%=12.5$

Step 2:Calculation for empirical formula of the compound.

Element	% Composition	Atomic mass	Atomic ratio	Simple ratio
$\mathrm{Nitrogen}$ $\mathrm{Hydrogen}$	$87.5$ $12.5$	$14$ $1$	$\frac{87.5}{14}=6.25$ $12.5$	$\frac{6.25}{6.25}=1$ $\frac{12.5}{6.25}=2$

Thus, the empirical formula is ${\mathrm{NH}}_2$