Example 15.6 3 A closed 3.50 dm³ vessel initially containing 0.020 mole of PCI, dissociates thermally on heating to give phosphorus (III) chloride and chlorine. What is the total pressure at 300°Cwhen the equilibrium is achieved (Kc at 300 °C = 4.38 x 102 mol¹dm³) 0 -3