Consider the following reaction: NO (g) + SO 3 (g) ⇌ NO 2 (g) + SO 2 (g) A reaction mixture initially contains 0.86 atm NO and 0.86 atm SO 3. Determine the equilibrium pressure of NO 2 if K p for the reaction at this temperature is 0.0118. 0.048 atm 0.012 atm 0.85 atm 0.084 atm 0.78 atm

The equilibrium pressure of NO2 is 0.084 atm

Explanation:

Step 1: Data given

A reaction mixture initially contains 0.86 atm NO and 0.86 atm SO3.

Kp = 0.0118

Step 2: The balanced equation

NO (g) + SO3 (g) ⇌ NO2 (g) + SO2 (g)

Step 3: The initial pressures

p (NO) = 0.86 atm

p (SO3) = 0.86 atm

p (NO2) = 0 atm

p (SO2) = 0 atm

Step 4: The pressure at the equilibrium

For 1 mol NO we need 1 mol SO3 to produce 1 mol NO2 and 1 mol SO2

p (NO) = 0.86 - x atm

p (SO3) = 0.86 - xatm

p (NO2) = x atm

p (SO2) = x atm

Step 5: Define Kp

Kp = ((pNO2) * (pSO2)) / ((pNO) * (pSO3))

Kp = 0.0118 = x² / (0.86 - x) ²

X = 0.08427

p (NO) = 0.86 - 0.08427 = 0.77573 atm

p (SO3) = 0.86 - 0.08427 = 0.77573 atm

p (NO2) = 0.08427 atm

p (SO2) = 0.08427 atm

The equilibrium pressure of NO2 is 0.08427 atm ≈ 0.084 atm