Question

For the following reaction, Kc = 255 at 1000 K. CO (g) + Cl2 (g) ⇌ COCl2 (g) A reaction mixture initially contains a CO concentration of 0.1530 M and a Cl2 concentration of 0.174 M at 1000 K.

What is the equilibrium concentration of COat 1000 K?

What is the equilibrium concentration of Cl2at 1000 K?

What is the equilibrium concentration of COCl2at 1000 K?

Answer 1

[CO] = 0.0150M

[Cl2] = 0.0360M

[COCl2]= 0.1380M

Explanation

CO(g) + Cl2(g) <-------> COCl2(g)

Kc = [COCl2]/([CO] [Cl2]) = 255

Initial concentration

[CO] = 0.1530

[Cl2]= 0.1740

[COCl2]= 0

change in concentration

[CO] = - x

[Cl2] = - x

[COCl2] = +x

equillibrium concentration

[CO] = 0.1530 - x

[Cl2] = 0.1740 - x

[COCl2] = x

Therefore

x/((0.1530 - x)(0.1740 - x)) = 255

solving for x

x = 0.1380

Therefore, at equillibrium

[CO] = 0.1530 - 0.1380 = 0.0150M

[Cl2]= 0.1740 - 0.1380 = 0.0360M

[COCl2] = 0.1380M