Answer
48.5 g $NH_{4}NO_{3}$ contains 17.0 g N.
Work Step by Step
Strategy: : 1- find the Molar mass of $NH_{4}NO_{3}$ 2- Calculate the percentage of nitrogen in $NH_{4}NO_{3}$3 - Calculate the amount of N in the given amount of $NH_{4}NO_{3}$
Molar mass of $NH_{4}NO_{3}$ = 2 x 14.0 + 4 x 1.01 + 3 x 16.0
Molar mass of $NH_{4}NO_{3}$ = 80.0 g/mol ( to three significant figures)
Based on the chemical formula $NH_{4}NO_{3}$, in 1 mole of ammonium nitrate, there are 2 moles of N, 4 moles of H, and 3 moles of O.
Mass percentage of N = $\frac{mass_(2 N moles)}{Molar mass_(NH_{4}NO_{3}) }$$\times$100%
Mass percentage of N = $\frac{2 \times 14.01 g}{80.0 g }$ $\times$ 100%
Mass percentage of N = 35.0%
The mass of N in 48.5 g in $NH_{4}NO_{3}$ is 35% of 48.5 g :
35%$\times$48.5g = $\frac{35}{100}\times48.5g$
The mass of N in 48.5 g $NH_{4}NO_{3}$ is 17.0 g
