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3. N2(g) + 3H2(g) → 2NH3(g) How many liters of hydrogen gas are needed to react completely with 5.2L of nitrogen gas at STP?

User Alex Chernyshev
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1 Answer

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Step-by-step explanation:

We have to find the volume of H₂ that is needed to react with 5.2 L of N₂ at STP.

One mol of any gas at STP occupies 22.4 L. We can use that relationship to find the number of moles of N₂ that are present in 5.2 L of it.

1 mol of N₂ = 22.4 L

moles of N₂ = 5.2 L * 1 mol /(22.4 L)

moles of N₂ = 0.232 mol

N₂ (g) + 3 H₂ (g) ----> 2 NH₃ (g)

According to the coefficients of the reaction 1 mol of N₂ will react with 3 moles of H₂. So, the molar ratio between N₂ and H₂ is 1 to 3. We can use that relationship to find the number of moles of H₂ that will be needed to completely react with 0.232 moles of N₂.

1 mol of N₂ = 3 moles of H₂

moles of H₂ = 0.232 moles of N₂ * 3 moles of H₂/(1 mol of N₂)

moles of H₂ = 0.696 moles

And finally we can convert back the moles into liters.

1 mol of H₂ = 22.4 L (at STP)

volume of H₂ = 0.696 moles * 22.4 L/(1 mol)

volume of H₂ = 15.6 L

Answer: 15.6 L of hydrogen gas are needed to completly react with 5.2 L of nitrogen gas.

User Alexis Wilke
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