Phosphorus pentachloride, PCl5, is a gaseous compound that decomposes according to the following reaction:

PCl5 (g) ⇌ PCl3 (g) + Cl2 (g)

This decomposition is endothermic. A sample of 4.789 g of PCl5 is placed in a 0.500 L container and the temperature is raised to 350K.

a. What is the initial concentration of PCl5 in the container, before any decomposition occurs?

b. Write the expression for Kc for this reaction at equilibrium

c. If the temperature were raised to 500K, what effect would this have on the equilibrium constant, Kc? Explain.

Use the graph at right to answer the following questions:

d. Does this graph represent the forward reaction or the reverse reaction?

e. Label the time at which equilibrium is reached.

f. In the space below, sketch a possible potential energy diagram for the forward

reaction. Label the reactants, products, and activation energy for the reaction.

g. Describe two ways that the rate of the forward reaction could be increased.