Chemistry Equilibrium Problem

Question

The reaction H₂(g) + I₂(g)  2HI(g) has K_p = 45.9 at 763 K. A particular equilibrium mixture at 763 K contains HI at a pressure of 3.35 atm and H₂ at a pressure of 2.53 atm. Calculate the equilibrium pressure of I₂(g) in this mixture.

Answer 1

H₂(g) + I₂(g)  <==>  2HI(g)

2.53 atm...?...............3.35 atm......Equilibrium pressures

Kp = 45.9 = (HI)² / (H₂)(I₂)

4.59 = (3.35)² / (2.53)(I₂)

(I₂) = (3.35)² / (45.9)(2.53)

(I₂) = 0.0966 atm