If you had 15 grams of nitrogen gas mixed with 4 grams of hydrogen, what would the maximum amount (in grams) of ammonia that would be theoretically produced?

Question

balenced reaction: N2 (g) + 3H2 (g)  2NH3 (g)

_{If you had 15 grams of nitrogen gas mixed with 4 grams of hydrogen, what would the maximum amount (in grams) of ammonia that would be theoretically produced?}

 

Answer 1

Theoretical yield:

N₂(g) + 3H₂(g) ==> 2NH₃(g) ... balanced equation

Using the information provided, the stoichiometry of the balanced equation and dimensional analysis, we can answer the question of what is the theoretical yield.

Anytime you are given the amount of BOTH reactants, you must find which of them is in limiting supply. We can do this by calculating the moles or mass of product formed from each.

For N₂: 15 g N₂ x 1 mol N₂/28 g x 2 mol NH₃ / mol N₂ x 17 g NH₃/mol NH₃ = 18.2 g NH₃ from 15 g N₂

For H₂: 4 g H₂ x 1 mol H₂/2 g x 2 mol NH₃ / 3 mol H₂ x 17 g NH₃/mol NH₃ = 22.7 g NH₃ from 4 g H₂

From this we see that N₂ is LIMITING and theoretical yield = 18.2 g NH₃