For the following reaction, KcKc = 255 at 1000 KK.
CO (g) + Cl2 (g) ⇌ COCl2 (g)CO (g) + Cl2 (g) ⇌ COCl2 (g)
A reaction mixture initially contains a COCO concentration of 0.1550 MM and a Cl2Cl2 concentration of 0.173 MM at 1000 KK.

a) What is the equilibrium concentration of COCO at 1000 KK?

b) What is the equilibrium concentration of Cl2Cl2 at 1000 KK?

c) What is the equilibrium concentration of COCl2COCl2 at 1000 KK?

Answer :

The equilibrium concentration of CO is, 0.016 M

The equilibrium concentration of Cl₂ is, 0.034 M

The equilibrium concentration of COCl₂ is, 0.139 M

Explanation :

The given chemical reaction is:

Initial conc.      0.1550      0.173           0

At eqm.          (0.1550-x)  (0.173-x)         x

As we are given:

The expression for equilibrium constant is:

Now put all the given values in this expression, we get:

x = 0.139 and x = 0.193

We are neglecting value of x = 0.193 because equilibrium concentration can not be more than initial concentration.

Thus, we are taking value of x = 0.139

The equilibrium concentration of CO = (0.1550-x) = (0.1550-0.139) = 0.016 M

The equilibrium concentration of Cl₂ = (0.173-x) = (0.173-0.139) = 0.034 M

The equilibrium concentration of COCl₂ = x = 0.139 M