Is the decomposition of dinitrogen tetroxide to nitrogen dioxide is in equilibrium total pressure of 1.5 bar and a temperature of 298K?

Question

State whether the decomposition of dinitrogen tetroxide to nitrogen dioxide is in equilibrium when the reaction is at a total pressure of 1.5 bar and a temperature of 298K. The mole fraction of dinitrogen tetroxide at equilibrium is 0.6.

i. If not in balance, indicate: i. in which direction the reaction would move to reach it.

ii. At what temperature would the system have to be to reach equilibrium under the conditions described in the exercise.

Answer 1

Dinitrogen tetroxide = N₂O₄

Nitrogen dioxide = NO₂

Decomposition reaction:

N₂O₄ ==> 2NO₂

mole fraction N₂O₄ x Total pressure = pressure of gas N₂O_4

pressure N₂O₄ = 0.6 x 1.5 bar = 0.9 bar

pressure NO₂ = 0.4 x 1.5 bar = 0.6 bar

Q = (0.6)2 /(0.9) = 0.4

Compare this value of Q to the K_p for the reaction (it should be given to you in the problem).

If K is not given, but ∆G is, you can calculate K.

If Q = K, the reaction is at equilibrium

If Q > K, the reaction will want to go toward the left and if Q < K, vice versa.

The temperature for equilibrium will be solved from ∆G = ∆H - T∆S, and set ∆G = 0 and solve for T (in Kelvin)

I don't think you provided enough information (∆G, ∆H, ∆S, Kp, etc) for us to provide a complete answer.