Question 18 (5 points) The following equilibrium is established in a closed, rigid container PCs (g) + heat --- PCI, (g) + Cl (8) In which direction does the reaction shift as a result of each of the following changes? a. adding additional phosphorus pentachloride gas, PCI> () b. removing chlorine gas, Cly (8) c. decreasing the temperature d. increasing the pressure by adding helium gas (an inert gas) o using a catalyst