When the system comes to equilibrium at a given temperature, PHI = 0.738 atm, and PH2 = PI2 = 0.08137 atm . What is the value of Kp at this temperature?

Question

Hydrogen iodide gas decomposes to molecular hydrogen and iodine as shown in the equilibrium below.

2HI (g)  H₂(g) + I₂(g).

(Recall: K_p is an equilibrium constant written in terms of pressures rather than concentrations.)

Answer 1

Kp = (H2)(I2) / (HI)²

Kp = (0.08137)(0.08137) / (0.738)²

Kp = 0.0122