At stp a 22.4 liter sample of nh3(g) contains the same number of molecules as

At STP a 22.4 liter sample of ammonia contains the same number of molecules as one mole.

At standard temperature and pressure 1 mol of gas occupied 22.4 liters:
V(NH₃) = 22.4 L; volume of water.
Vm = 22.4 L/mol; molar volume at STP.
n(NH₃) = V ÷ Vm.
n(NH₃) = 22.4 L ÷ 22.4 L/mol.
n(NH₃) = 1 mol; amount of substance.
N(NH₃) = n(NH₃) · Na.
N(NH₃) = 1 mol · 6.022·10²³ 1/mol.
N(NH₃) = 6.022·10²³; number of molecules.
Na - Avogadro number or constant.