Question

The equilibrium constant for the reaction
COCl2 (g) CO (g) + Cl2 (g) is Kc = 4.63 ´ 10–3 at 527 °C
If 10 g of COCl2(g) is placed in a 1 L container, determine how much Cl2 is present at equilibrium.

Answer 1

Answer: The concentrations of $Cl_2$ at equilibrium is 0.023 M

Explanation:

Moles of  $Cl_2$ = $\frac{\text {given mass}}{\text {Molar mass}}=\frac{10g}{71g/mol}=0.14mol$

Volume of solution = 1 L

Initial concentration of $Cl_2$ = $\frac{0.14mol}{1L}=0.14M$

The given balanced equilibrium reaction is,

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

Initial conc.           0.14 M           0 M       0M    

At eqm. conc.     (0.14-x) M        (x) M        (x) M

The expression for equilibrium constant for this reaction will be,

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

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

$4.63\times 10^{-3}=\frac{x)^2}{(0.14-x)}$

By solving the term 'x', we get :

x = 0.023 M

Thus, the concentrations of $Cl_2$ at equilibrium is 0.023 M