Question: how many hydrogen atoms are present in 0.325 g of nh3?
Answer: The number of moles in 27.6g ammonia is 27.6 ÷ 17 = 1.62 mol. A mole is 6.02 × 10²³, so the number of hydrogen atoms in a 1.62 moles of ammonia is 1.62 × 6.02 × 10²³ × 3 = 2.93 × 10²⁴ atoms.