Answer to Question #9729 in Physical Chemistry for Sandra

Question

How do you calculate the kp of the reaction N2O4(g)<-->2NO2(g) if 0.01262M of NO2 are made at 723 mmHg and 298K?

Answer 1

K_p = K_c(RT)
K_c = [NO₂]²/[N₂O₄]

[N₂O₄] is unknown.
In the case when the concentration [N₂O₄] is known, the constant will have the form

K_p = [NO₂]²/[N₂O₄] * (RT)
K_p = (0.01262)²/[N₂O₄] * 8.31*298