# What is the percentage composition by mass of nitrogen in ammonia?

Aug 30, 2017

#### Answer:

Well it is simply "Mass of nitrogen"/"Mass of nitrogen and hydrogen"xx100%

#### Explanation:

And thus taking molar masses......we get:

(14.01*g*mol^-1)/(14.01*g*mol^-1+3xx1.00794*g*mol^-1)xx100%

~=80%

Aug 30, 2017

#### Answer:

The mass percent of $\text{N}$ in ${\text{NH}}_{3}$ is 82.244%.

#### Explanation:

Divide the mass of $\text{N}$ by the mass of ${\text{NH}}_{3}$, then multiply by $100$

The chemical formula for ammonia is ${\text{NH}}_{3}$. The formula indicates that in each mole of ${\text{NH}}_{3}$, there is one mole of $\text{N}$ atoms.

The molar mass of ammonia is $\text{17.031 g/mol}$. The molar mass of $\text{N}$ is $\text{14.007 g/mol}$.

$\text{mass percent N}$$=$(14.007color(red)cancel(color(black)("g/mol")))/(17.031color(red)cancel(color(black)("g/mol")))xx100="82.244%"