When 1.000 mol of PCl5 is introduced into a 5.000-L container at 500 K, 78.50% of the PCl5 dissociates to give an equilibrium mixture of PCl5, PCl3, and Cl2: PCl5(g) ⇌ PCl3(g) + Cl2(g). (a) Calculate the values of Kc and Kp.

The equilibrium constant, Kc, quantifies the ratio of the concentrations of products to reactants at equilibrium for a reversible reaction. It is calculated using the formula Kc = [PCl3][Cl2] / [PCl5], where the brackets denote molarity. A larger Kc value indicates a greater extent of reaction towards products, while a smaller Kc suggests a preference for reactants.

Kp is the equilibrium constant expressed in terms of partial pressures of gases. It is related to Kc through the equation Kp = Kc(RT)^(Δn), where Δn is the change in moles of gas between products and reactants, R is the ideal gas constant, and T is the temperature in Kelvin. This relationship allows for the conversion between concentration-based and pressure-based equilibrium constants.

Dissociation refers to the process where a compound breaks down into its constituent parts, such as PCl5 dissociating into PCl3 and Cl2. Understanding stoichiometry is crucial for calculating equilibrium concentrations, as it involves using the initial amounts and the extent of dissociation to determine the final concentrations of all species involved in the reaction.