Chapter 14.2, Problem 2PE

Carbonyl chloride (COCl₂), also called phosgene, was used in world war I as a poisonous gas. The equilibrium concentrations for the reaction between carbon monoxide and molecular chlorine to form carbonyl chloride

$\text{CO}(g)+{\text{Cl}}_2(g)\rightleftharpoons {\text{COCl}}_2(g)$

at 74°C are [CO] = 1.2 × 10⁻² M, [Cl₂] = 0.054 M, and [COCl₂] = 0.14 M. Calculate the equilibrium constant (K_c).