Question

Ammonia will decompose into nitrogen and hydrogen at high temperature. An industrial chemist studying this reaction fills a 5.0L flask with 4.5 atm of ammonia gas, and when the mixture has come to equilibrium measures the amount of nitrogen gas to be 1.1 atm. Calculate the pressure equilibrium constant for the decomposition of ammonia at the final temperature of the mixture. Round your answer to 2 significant digits.

Answer 1

Kp = 7.4727

Step-by-step explanation:

Let's write the balanced equilibrium reaction:

2NH₃ <-------> N₂ + 3H₂ Kp = ??

Now, if we want to calculate the Kp, we need to write an ICE chart with this reaction, which is the following:

2NH₃ <-------> N₂ + 3H₂

I. 4,5 0 0

C. -2x +x +3x

E. 4,5-2x x 3x

According to this chart, the Kp expression should be:

Kp = (PH₂)³ * (PN₂) / (PNH₃)² (1)

The value of x, we already know it because the problem states that the amount of nitrogen gas is 1.1 atm, so replacing this value into (1) we have:

Kp = (3*1.1)³ * (1.1) / (4.5 - (2 * 1.1))²

Kp = 39.5307 / 5.29

Kp = 7.4727

Hope this helps