What is the mass of nitrogen in a 10g sample of pure ammonium nitrate?

10 g of NH₄NO₃ has 3.5 g of N

Explanation:

Formula for ammonium nitrate is: NH₄NO₃

1 mol of NH₄NO₃ has 4 moles of H, 2 moles of N, and 3 moles of O

1 mol of NH₄NO₃ weighs 80 g

If 80 grams of salt has 2 moles of N

10 g of salt will have (10.2) / 80 = 0.25 moles of N

1 mol of N, weighs 14 g

0.25 mol. 14 g/mol = 3.5 grams of N