Chapter 8, Problem 8.47E

At $600°\text{C}$, gaseous $\text{CO}$ and ${\text{Cl}}_2$ are mixed together in a closed container. At the instant they are mixed, their concentrations are $\text{CO}=0.79\text{mol}/\text{L}$ and ${\text{Cl}}_2=0.69\text{mol}/\text{L}$. After equilibrium is established, their concentrations are $\text{CO}=0.25\text{mol}/\text{L}$ and ${\text{Cl}}_2=0.15\text{mol}/\text{L}$. Evaluate the equilibrium constant for the reaction

$\text{CO}\left(\text{g}\right)+{\text{Cl}}_2\left(\text{g}\right)\rightleftarrows {\text{COCl}}_{\text{2}}\left(\text{g}\right)$