Calculate the equilibrium pressure of each gas at 700 K.

Question

A mixture of 0.683 atm ClF30.683 atm ClF3 , 0.545 atm F20.545 atm F2 , and 0.427 atm ClF0.427 atm ClF is heated in a closed vessel to 700 K700 K .

ClF3(g)↽−−⇀ClF(g)+F2(g)𝐾p=0.140 at 700 KClF3(g)↽−−⇀ClF(g)+F2(g)Kp=0.140 at 700 K

Calculate the equilibrium pressure of each gas at 700 K.

Answer 1

ClF₃(g) <===> ClF(g) + F₂(g) Kp = 0.140

0.683..................0.427.......0.545.....Initial

Q = (ClF)(F₂) / (ClF₃) = (0.427)(0.545) / 0.683)

Q = 0.341 which is > than Kp, so reaction will proceed to the left (reactant side)

ClF₃(g) <===> ClF(g) + F₂(g)

0.683..................0.427.......0.545.....Initial

+x.......................-x............-x............Change

0.683+x.............0.427-x....0.545-x...Equilibrium

Kp = 0.140 = (0.427-x)(0.545-x) / (0.683+x)

Solve for x and then

PClF₃ = 0.683+x

PClF = 0.427-x

PF₂ = 0.545-x