Stoichiometry, Chemistry

Question

How many moles of NH3 can be produced from 12.0 mol of H2 and excess N2?

Answer 1

the underlying balanced equation here is

N2​(g) + 3H2​(g) → 2NH3​(g)

which tells us based on the coefficients that the molar ratio is 2 mol NH₃: 3 mol H₂

from there then you can take

12 mol H2 x 2 mol NH3/ 3 mol H2 = 8 mol NH3

meaning that 8.0 moles of NH₃ can be produced

Answer 2

First, you must write the correctly balanced chemical equation for the reaction taking place:

3H₂ + N₂ ==> 2NH₃

Inspection shows you that 3 moles of hydrogen react with 1 mole of nitrogen to produce 2 moles ammonia.

Using dimensional analysis:

12.0 moles H₂ x 2 moles NH₃/3 moles H₂ = 8 moles NH₃ can be produced

Using proportions:

3 moles H₂/2 moles NH₃ = 12.0 moles H₂/x moles NH₃

3x = 24

x = 8 moles NH₃ can be produced