If, at a given temperature, the equilibrium constant for the reaction H2(g) Cl2(g) 2HCl(g) is Kp, then the equilibrium constant for the reaction HCl(g) (1/2) H2(g) (1/2)Cl2 (g) can be represented as:

Kp = [(PH2/P°)∧(1/2)eq]*[(PCl2/P°)∧(1/2)eq] / (PHCl(g)/P°)eq

Explanation:

∴ Kp = F(T)

⇒ Kp = (PHCl/P°)eq / [(PCl2/P°)eq]*[(PH2/P°)eq]

∴ P° = 1 bar

⇒ Kp = [(PH2/P°)∧(1/2)eq]*[(PCl2/P°)∧(1/2)eq] / (PHCl(g)/P°)eq

po-215 i got it right on the quiz