Calculate the maximum number of grams of NH3 that can be produced by the reaction of 2.00g of N2 with 3.00g H2

Question

Reaction: N2(g)+3 H2(g)>>>2 NH3(g)

Answer 1

Approximately 2.43 grams.

You need to find how many moles of ammonia can be produced, so you need to find out which is your limiting reagent. Therefore, step one is to calculate the moles of each reagent. You do that by dividing the mass by the molecular weight. That will give you in this case the gram-moles of each reagent.

N2 moles = 2 g / 28 g/gmol = .0714 gmol

H2 moles = 3 g / 2 g/gmol = 1.5 gmol

N2 is the limiting reagent.

according to the chemical formula you will make 2 mol of ammonia for every 1 mol of nitrogen so we can make how many moles of ammonia?

.0714*2 = 0.143 gmols.

Now to convert gmols to grams we use the molecular weight of ammonia, which is 14+3 = 17.

mass of ammonia = 0.143 * 17 = 2.43 grams.

Note that the molecular weights used here are approximate and so the answer is off by a few percent. To be more exact look up the molecular weights and then perform these calculations again using the more exact figures.