How many molecules (not moles) of nh3 are produced from 5.81*10-4 g of h2? express your answer numerically as the number of molecules?

The reaction of formation of NH₃ is as follows;

N₂ + 3H₂ - - - > 2NH₃

the stoichiometry of H₂ to NH₃ is 3:2

for every 3 moles of H₂ that reacts, 2 moles of NH₃ are produced

the mass of H₂ that has been used up = 5.81 x 10⁻⁴ g

molar mass of H₂ = 2 g/mol

number of H₂ moles that were used up = 5.81 x 10⁻⁴ g / 2 g/mol

= 2.905 x 10⁻⁴ mol

for every 3 mol of H₂ used up - 2 moles of NH₃

for every 1 mol of H₂ used up - 2/3 moles of NH₃

therefore for 2.905 x 10⁻⁴ mol of H₂ = 2/3 x 2.905 x 10⁻⁴ mol

number of NH₃ moles produced = 1.94 x 10⁻⁴ mol

number of NH₃ molecules in 1 mole = 6.022 x 10²³ molecules

therefore in 1.94 x 10⁻⁴ mol = 6.022 x 10²³ molecules/mole x 1.94 x 10⁻⁴ mol

therefore number of NH₃ molecules produced = 1.168 x 10²⁰ NH₃ molecules