Question

D Question 12 What is the pressure of BrClin an equilibrium mixture of Cly, Bry, and BrClif the initial pressure of Cly in the mixture is 0.18 atm and the initial pressure of Bry in the mixture is 0.535 atm? Cl, G) + Bry() = 2BC1 (9) Kp 4.7 x 10-2

Answer 1

ICE Table:

p(012) p(Br2) p(Brči) initial 0.18 0.535 change - 1x -1x +2x equilibrium 0.18-1x 0.535-1x +2x

Equilibrium constant expression is

Kp = p(BrCl)^2/p(Cl2)*p(Br2)

0.047 = (4*x^2)/((0.18-1*x)(0.535-1*x))

0.047 = (4*x^2)/(9.63*10^-2-0.715*x + 1*x^2)

4.526*10^-3-3.361*10^-2*x + 4.7*10^-2*x^2 = 4*x^2

4.526*10^-3-3.361*10^-2*x-3.953*x^2 = 0

This is quadratic equation (ax^2+bx+c=0)

a = -3.953

b = -3.361*10^-2

c = 4.526*10^-3

Roots can be found by

x = {-b + sqrt(b^2-4*a*c)}/2a

x = {-b - sqrt(b^2-4*a*c)}/2a

b^2-4*a*c = 7.27*10^-2

roots are :

x = -3.835*10^-2 and x = 2.985*10^-2

since x can't be negative, the possible value of x is

x = 2.985*10^-2

At equilibrium:

p(BrCl) = +2x = +2*0.02985 = 0.05971 atm

Answer:

p(BrCl) = 0.0597 atm