Calculate the number of atoms in 10 litres of ammonia (N=14,H=1).

As 1 molecule NH3 contain 4 atoms.

Therefore 1 mole of NH3 contain 4 moles of atoms.

As 1 mole = 6.022 × 10²³ atoms.

Therefore,

1 mole of ammonia contain = 4 × 6.022 × 10²³ atoms.

As we known at STP. 1 mole of any gas occupies a constant volume i.e. 22.4 L

Hence in 22.4 L contain → 24.08 × 10²³ atoms

∴ 1 L contain → (24.08 × 10²³) / 22.4 atoms

∴ 10 L contain → (1.07 × 10²³) × 10 atoms

Hence 10 Liter of ammonia gas contain 10.7 × 10²³ atoms or we can say 1.07× 10²⁴ atoms.