Practice problems

[Lucas Lopez]

I was trying do some practice problems and I am unsure on how to proceed for a problem like this:

In a mixture of N 2 and H 2 in the ratio 1:3 at 30 atm and 300C, the % of NH 3 at equilibrium is 17.8. Calculate Kp for N2+3H2 ⇌2NH3

[hiranya sundar 2D]

Here's how I would approach the problem:

1/4* 30atm = the partial pressure of N2 = 7.5 atm
3/4* 30atm = the partial pressure of H2 = 22.5 atm

Then I would calculate an Ice table:
N2 H2 NH3
I 7.5 22.5 0
C -x -3x +2x
E 7.5-x 22.5-3x .178*30

And then I would say 2x = .178*30, and solve for x to find each concentration.

Please let me know if this is correct if you were given the answer to this problem! I'm also a little unsure how to interpret the 17.8% in the context of the question, as well as if the total pressure of reactants is the same are products after a reaction because that's the only way I figure I could do this problem!