To answer this question, we can use the balanced chemical equation for the reaction between hydrogen gas (H2) and nitrogen gas (N2) to form ammonia (NH3):
N2 + 3H2 → 2NH3
From the balanced equation, we can see that 3 moles of hydrogen gas are required to react with 1 mole of nitrogen gas to form 2 moles of ammonia.
First, we need to calculate the number of moles of hydrogen gas we have:
n(H2) = m/M = 14.2 g / 2.016 g/mol = 7.05 mol
Next, we can use the mole ratio between hydrogen and nitrogen from the balanced equation to calculate the number of moles of nitrogen gas required:
n(N2) = n(H2) / 3 = 7.05 mol / 3 = 2.35 mol
Finally, we can use the molar mass of nitrogen gas to convert from moles to grams:
m(N2) = n(N2) x M(N2) = 2.35 mol x 28.02 g/mol = 65.9 g
Therefore, 65.9 grams of nitrogen gas is required to completely react with 14.2 grams of hydrogen gas at STP.
Hope this Helps!