How many total atoms are there in 15.7 g of ammonia ( NH3 )?

Answer 1

NH₃ = ammonia; molar mass = 14.0 + (3x1.01) = 14.0 + 3.03 = 17.0 g / mol (3 sig.figs.)

15.7 g NH₃ x 1 mol NH₃ / 17.0 g = 0.9235 moles NH₃

0.9235 moles NH₃ x 6.022x10²³ molecules NH₃ / mole = 5.56x0²³ molecules of NH₃

each molecule of NH³ contains 4 atoms (1 N atom and 3 H atoms)

Total atoms = 5.56x10²³ molecules x 4 atoms / molecule = 2.22x10²⁴ atoms