A mixture of 0.5940 M CO and 0.3950 M Cl2 is enclosed in a vessel and heated to 1000 K . CO(g)+Cl2(g)↽−−⇀COCl2(g)c=255.0 at 1000 K Calculate the equilibrium concentration of each gas at 1000 K

[CO] = 0.2064M

[Cl2] = 0.0074M

[COCl2] = 0.3876M

Explanation:

Based on the reaction, Kc at 1000K is:

Kc = 255.0 = [COCl2] / [CO] [Cl2]

Where [] are concentrations at equilibrium

As the reaction is 1:1, the concentrations at equilibrium are:

[CO] = 0.5940M - X

[Cl2] = 0.3950M - X

[COCl2] = X

Where X is reaction coordinate

Replacing:

255.0 = [X] / [0.5940 - X] [0.3950 - X]

255.0 = X / 0.23463 - 0.989 X + X²

59.8307 - 252.195 X + 255 X² = X

59.8307 - 253.195 X + 255 X² = 0

Solving for X:

X = 0.605M. False solution because produce negative answers

X = 0.3876M. Right solution.

Replacing:

[CO] = 0.5940M - 0.3876M

[Cl2] = 0.3950M - 0.3876M

[COCl2] = 0.3876M

[CO] = 0.2064M

[Cl2] = 0.0074M

[COCl2] = 0.3876M