At 100 °C, Keq = 1.5E8 for the reaction:
$$CO(g) + Cl_2(g) \rightleftharpoons COCl_2(g)$$
Using appropriate approximation, calculate the partial pressure of CO at 100 °C at equilibrium in a chamber that initially contains $$COCl_2$$ at a pressure of 0.283 bar.