20.0 grams of ammonia are produced in the reaction between nitrogen and hydrogen. How many grams of each of the two gases were used up in this reaction?

Answer 1

Write the balanced equation:

N₂(g) + 3H₂(g) ==> 2NH₃(g)

Convert mass to moles:

20.0 g NH₃ x 1 mole NH₃/17 g = 1.18 moles NH₃

Determine mass of each reactant required:

mass N₂ required = 1.18 mole NH₃ x 1 mol N_2/2 mol NH₃ x 28 g N₂/mol = 16.5 g N₂ required

mass H₂ required = 1.18 mole NH₃ x 3 mol H₂/2 mol NH₃ x 2 g H₂/mol = 3.54 g H₂ required