Question

Consider: CO(g) + Cl2 (g) ⇌ COCl2 (g) Kc = 1.2×103 at 395 °C. If the equilibrium concentrations of Cl2 and COCl2 are the same at 395 °C, find the equilibrium concentration of CO in the reaction.

Answer 1

Answer : The equilibrium concentration of CO in the reaction is, $8.3\times 10^{-4}M$

Explanation :

The given chemical reaction is:

$CO(g)+Cl_2(g)\rightleftharpoons COCl_2(g)$

The expression for equilibrium constant is:

$K_c=\frac{[COCl_2]}{[CO][Cl_2]}$

As we are given:

Concentration of $Cl_2$ at equilibrium = Concentration of $COCl_2$

So,

$K_c=\frac{[Cl_2]}{[CO][Cl_2]}$

$K_c=\frac{1}{[CO]}$

$1.2\times 10^3=\frac{1}{[CO]}$

$[CO]=8.3\times 10^{-4}M$

Therefore, the equilibrium concentration of CO in the reaction is, $8.3\times 10^{-4}M$