At 200 °C, the equilibrium constant (K_p) for the reaction below is 2.40 × 10³. 2NO (g) N₂ (g) + O₂ (g)
A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O₂ is ________ atm.

Question

At 200 °C, the equilibrium constant (K_p) for the reaction below is 2.40 × 10³. 2NO (g)

N₂ (g) + O₂ (g)
A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O₂ is ________ atm.

Quizplus · Accepted Answer

Using the equilibrium constant and the initial pressure of NO, we can set up an ICE (Initial, Change, Equilibrium) table:

NO:       36.1 atm      -2x         36.1 - 2x
O2:         0 atm        +x              x
N2:         0 atm        +x              x

The equilibrium constant expression is K = (PO2)(PN2)/(PNO)^2 = 2.40×10^13.

Plugging in the equilibrium concentrations gives:

K = (x)(x)/(36.1-2x)^2

Solving for x gives x = 17.9 atm. Therefore, the partial pressure of O2 is 17.9 atm at equilibrium.

The correct answer is (C).

At 200 °C, the Equilibrium Constant (Kp)for the Reaction Below