Consider the following equilibrium reaction, PCl5(gas) ↔ PCl3(gas) + Cl2(gas). If a 1-liter flask contains 0.02 moles of PCl3 and 0.02 moles of Cl2 at equilibrium, how many moles of PCl5 are in the flask. Assume the equilibrium constant is 5 × 10^-2.