How many atoms in a 4.25 gm NH3

 

Molar mass of NH₃ = 17 g

1 mol NH₃ Ξ 6.023 × 10²³ molecules of NH₃

1 molecule of NH₃ ≡ 4 atoms (1 atom of N + 3 atoms of H)

So, 6.023 × 10²³ × 4 = 24.092 × 10²³ atoms in 1 mole NH₃

17 g NH₃ Ξ 17 / 4.25 = 4 moles NH₃

4 moles NH₃ = 4 × 24.092 × 10²³ atoms = 96.368 ×10²³ atoms