N2 + 3H2 → 2NH3 How many grams of ammonia (NH3) is produced when 12grams of hydrogen react?

Answer 1

So we : N₂ + 3H₂ --> 2NH₃

We want to know how much NH₃ we get out at the end if we have a 12 grams of hydrogen. We have to make an assumption that we have endless N₂ because it is not stated that we have a quantity to consider. Therefore, we will assume the entire 12 grams of hydrogen goes towards forming the product. Lets begin by first converting the units to something usable: moles!

12grams of hydrogen / (2grams/mol) {this is because hydrogen is diatomic in this equation} = 6 moles of H₂.

Great something we can work with!

Now we need to consider the stoichiometry to get our answer. The hydrogen is in a 3:2 ratio with ammonia, which means that for every 3 hydrogen molecules we will get 2 ammonia (therefore, we know we need to have less moles of ammonia than hydrogen molecule moles at the end). Great that we understand this piece we are all set to get our answer!

6 moles of diatomic hydrogen X (moles of ammonia/ moles of diatomic hydrogen) = our answer.

Therefore, 6 x (2/3) = 4 moles of ammonia.

Hopefully you found this answer insightful and hopefully this helps. This of course assumes we have endless diatomic nitrogen to react with.