Calculate the equilibrium constnat for the reaction given below at `400K`, if `DeltaH^(Theta) = 77.2 kJ "mole"^(-1)` and `DeltaS^(Theta) = 122 J K^(-1) "mole"^(-1)`.
`PCI_(5)(g) rarr PCI_(3)(g) +CI_(2)(g)`

Explanation

To calculate the equilibrium constant \( K_c \) for the reaction

\[ \text{PCl}_5(g) \rightleftharpoons \text{PCl}_3(g) + \text{Cl}_2(g) \]

at \( 400 \, K \), given the standard enthalpy change \( \Delta H^\circ = 77.2 \, \text{kJ/mol} \) and the standard entropy change \( \Delta S^\circ = 122 \, \text{J/K/mol} \), we will follow these steps:

...