Question

What is the percentage composition of ammonium nitrate, ${\mathrm{NH}}_4{\mathrm{NO}}_3$?

Answer 1

Step 1: Calculation of molecular mass of ${\mathrm{NH}}_4{\mathrm{NO}}_3$

The chemical formula for ammonium nitrate is ${\mathrm{NH}}_4{\mathrm{NO}}_3$.

$$\begin{gathered} {\mathrm{NH}}_4{\mathrm{NO}}_3=\left(\mathrm{Molar}\mathrm{mass}\mathrm{of}\mathrm{N}\times 2\right)+\left(\mathrm{Molar}\mathrm{mass}\mathrm{of}\mathrm{H}\times 4\right)+\left(\mathrm{Molar}\mathrm{mass}\mathrm{of}\mathrm{O}\times 3\right) \\ =\left(14\mathrm{g}{\mathrm{mol}}^{-1}\times 2\right)+\left(1\mathrm{g}{\mathrm{mol}}^{-1}\times 4\right)+\left(16\mathrm{g}{\mathrm{mol}}^{-1}\times 3\right) \\ =80\mathrm{g}{\mathrm{mol}}^{-1} \end{gathered}$$

Step 2: Calculation of percentage of nitrogen in ${\mathrm{NH}}_4{\mathrm{NO}}_3$

$$\begin{gathered} \mathrm{Percentage}\mathrm{of}\mathrm{Nitrogen}\mathrm{in}{\mathrm{NH}}_4{\mathrm{NO}}_3=\frac{\mathrm{Mass}\mathrm{of}\mathrm{N}\mathrm{in}{\mathrm{NH}}_4{\mathrm{NO}}_3}{\mathrm{Molecular}\mathrm{mass}\mathrm{of}{\mathrm{NH}}_4{\mathrm{NO}}_3}\times 100 \\ =\frac{28\mathrm{g}{\mathrm{mol}}^{-1}}{80\mathrm{g}{\mathrm{mol}}^{-1}}\times 100 \\ =35\% \end{gathered}$$

Step 3: Calculation of percentage of hydrogen in ${\mathrm{NH}}_4{\mathrm{NO}}_3$

$$\begin{gathered} \mathrm{Percentage}\mathrm{of}\text{hydrogen}\mathrm{in}{\mathrm{NH}}_4{\mathrm{NO}}_3=\frac{\mathrm{Mass}\mathrm{of}\text{H}\mathrm{in}{\mathrm{NH}}_4{\mathrm{NO}}_3}{\mathrm{Molecular}\mathrm{mass}\mathrm{of}{\mathrm{NH}}_4{\mathrm{NO}}_3}\times 100 \\ =\frac{4\mathrm{g}{\mathrm{mol}}^{-1}}{80\mathrm{g}{\mathrm{mol}}^{-1}}\times 100 \\ =5\% \end{gathered}$$

Step4. Calculation of percentage of oxygen in ${\mathrm{NH}}_4{\mathrm{NO}}_3$

$$\begin{gathered} \mathrm{Percentage}\mathrm{of}\text{oxygen}\mathrm{in}{\mathrm{NH}}_4{\mathrm{NO}}_3=\frac{\mathrm{Mass}\mathrm{of}\text{O}\mathrm{in}{\mathrm{NH}}_4{\mathrm{NO}}_3}{\mathrm{Molecular}\mathrm{mass}\mathrm{of}{\mathrm{NH}}_4{\mathrm{NO}}_3}\times 100 \\ =\frac{48\mathrm{g}{\mathrm{mol}}^{-1}}{80\mathrm{g}{\mathrm{mol}}^{-1}}\times 100 \\ =60\% \end{gathered}$$

Hence, the percentage composition of nitrogen, hydrogen, and oxygen is $35\%$, $5\%$, and $60\%$