Question

Ammonia is created in the Haber process in a rigid container (nitrogen gas plus hydrogen gas react to form ammonia gas). 10 moles of hydrogen gas are mixed with 5 moles of nitrogen gas. The initial pressure exerted on the container is 10 atm. Assuming the reaction runs to completion, what will the pressure (in atm) on the vessel be after the reaction takes place?

Answer 1

The final pressure inside the container will be 5atm.

Explanation:

According to the universal gas equation, the pressure of the gas is directly proportional to the number of moles of gas.

Or, P is proportional to n.

The equation of the reaction given here is 2N₂ + 3H₂ =2 NH₃.

So, 2 moles of nitrogen gas reacts with 3 moles of hydrogen gas.

Therefore, 5 moles of nitrogen gas reacts with 7.5 moles of hydrogen gas.

Amount of ammonia gas produced = 5 moles, because it's same as the moles of nitrogen gas utilized.

So hydrogen gas left in the container = $10 - 7.5$ moles = 2.5 moles

So, total moles of gas initially in the container = $10 +5$ moles = 15 moles.

Total moles of gas finally in the container =$5 +2.5$ moles = 7.5 moles.

Now,$\frac {P₁} {n₁}$=$\frac{ P₂} {n₂.}$

Or, $\frac{10} {15}$= $\frac{P2} {7.5}$.

Or, the final pressure = 5 atm.

So, the final pressure inside the container will be 5atm.