Question

An oxide of nitrogen is found to contain nitrogen and oxygen combined together in the ratio $7:16\;$ by mass. Derive formula of oxide and name it.

Answer 1

Nitrogen oxides are a group of seven gases and compounds are composed of Nitrogen and oxygen and sometimes they are collectively known as a$\left( {NOx} \right)$ gases it is a generic term for the nitrogen oxides, here to determine the oxide of nitrogen first we calculate the simplest ratio between nitrogen and oxygen, with the help of its atomic mass of oxygen and nitrogen.

Complete step-by-step answer: Nitrogen can react with oxygen to form numerous nitrogen oxides under different reaction conditions. Some of them are
${N_2}O$,$NO$,${N_2}{O_3}$,$N{O_2}$,${N_2}{O_5}$,$N{O_3}\;$and${N_2}{O_4}$. Nitric Oxide and Nitrogen Dioxide are common and hazardous gases both are formed during high temperature combustion in the atmosphere.
Now as per given in the question, Nitrogen and oxygen combined together in the ratio $7:16\;$by mass:

Element	Ratio by Mass (Given)	Atomic Mass	Mass ratio /atomic mass	Simplest Ratio
Nitrogen(N)	$7$	$14$	$\dfrac{7}{{14{\text{ }}}} = \dfrac{1}{2}$	$\dfrac{1}{2} \times 2 = 1$
Oxygen (O)	$16$	$16$	$\dfrac{{16}}{{16}} = \;1$	$1{\text{ }} \times {\text{ }}2 = 2$

The ratio by number of atoms can be found as a:
The given simplest ratio is $\left( 1 \right)$ for Nitrogen and$\;\left( 2 \right)$ for oxygen, It means that there are $\left( 1 \right)$ atom of Nitrogen and $\left( 2 \right)$ atom of oxygen.

Thus, the chemical formula is Nitrogen dioxide ($N{O_{2}}$).Therefore mass ratio of $N{O_{2}}\;$is $\dfrac{{14}}{{32}} = 7:16$

Note: Nitrogen oxides are produced in combustion processes, partly from nitrogen compounds in the fuel, but mostly by direct combination of atmospheric oxygen and nitrogen in flames. Nitrogen oxides are produced naturally by lightning, and also, to a small extent, by microbial processes in soils. Nitrogen oxides are harmful to the respiratory tract, eyes and skin and breathing Nitrogen Dioxide can irritate the nose and throat.