what mass of ammonia can be synthesized from 150g of h2?

Question

Can you please show steps as well? thank you!

Answer 1

First, write the correctly balanced equation:

3H₂(g) + N₂(g) ==> 2NH₃(g)

Since the amount of N₂ is not given, we must assume it is there in excess. This makes the amount of NH₃ formed dependent ONLY on how much H₂ is present (150g).

We always work in moles, so we next convert 150 g H₂(g) into moles:

150 g H₂ x 1 mol H₂/2.0 g H₂ = 75.0 moles H₂

Next, we look at the balanced equation to see the mole ratio of H₂ to NH₃ and note that it is 3 : 2, i.e. it takes 3 moles H₂ to make 2 moles NH₃. Using this ratio, we calculate moles of NH₃ formed from 75.0 moles H₂:

75 moles H₂ x 2 moles N₂/3 moles N₂ = 50.0 moles NH₃ formed.

Lastly, we convert moles NH₃ to grams of NH₃ using the molar mass of NH₃ (17 g/mol):

50 moles NH₃ x 17 g/mol = 850 g NH₃ formed from 150 g H₂