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