Question

An oxide of nitrogen contains $36.8$% by weight of nitrogen. The formula of the compound is:

• A. $N_{2}O$
• B. $N_2{O}_3$
• C. $NO$
• D. $N{O}_2$

Answer 1

Answer: (B)

$N_2{O}_3$

Let us assume the weight of the compound $=100gm$.

Weight of nitrogen $=36.8gm$

Moles of nitrogen $=\frac{36.8}{14}$

$\therefore$ Weight of oxygen $=100-36.8=63.2gm$

Moles of oxygen $=\frac{63.2}{16}$

The ratio of number of moles of $N$ and $O$ is,

$N:O=\frac{36.8}{14}$ : $\frac{63.2}{16}$

$=2.628:3.95$

$=1:1.5$

$=2:3$

So, formula is $N_2{O}_3$.