2 HI (g) ⇌ H₂ (g) + I₂ (g) At equilibrium, the partial pressure of HI is 1.9 atm and the partial pressures of H₂ and I₂ are 7.9 and 2.3 respectively. What is Kp for this equilibrium?

Answer 1

2 HI (g) ⇌ H₂ (g) + I₂ (g)

First, write the K_p constant expression (products on the top and reactant on the bottom, and coefficient as the exponent): K_p = P_H2P_I2 / P²_HI = (7.9 x 2.3) / (1.9)² = 5.0

Answer 2

2HI(g) <===> H₂(g) + I₂(g)

Kp = (P_H2) (P_I2) / P(HI)²

Kp = (7.9)(2.3) / (1.9)²

Kp = 18.17 / 3.61

Kp = 5.03