At 500 k, the reaction is at equilibrium with the following concentrations. [pci5]= 0.0095 m [pci3] = 0.020 [ci2] = 0.020 m what is the equilibrium constant for the given reaction? 0.042 0.42 2.4 24

Although it is omitted, the reaction equation for the decomposition of phosphorus pentachloride is:
PCl₅ → PCl₃ + Cl₂

The equilibrium constant's equation then becomes:
Kc = [PCl₃]*[Cl₂] / [PCl₅]
Kc = (0.02 * 0.02) / 0.0095
Kc = 0.042

The equilibrium constant is 0.042.