Equilibrium pressure of BrCl

Question

For the equilibriumBr2​+Cl2​<−−>2BrClthe equilibrium constant isKp=7.0at4000 K. If the cylinder is charged withBrClat an initial pressure of1.00 atmand the system allowed to come to equilibrium, what is the final (equilibrium) pressure ofBrCl

Answer 1

Br₂ + Cl₂ <==> 2BrCl Kp = 7.0

0.......0..............1.00.......Initial

+x....+x............-2x..........Change

x......x..............1 - 2x......Equilibrium

Kp = (BrCl)² / (Br₂)(Cl₂)

7.0 = (1-2x)² / (x)(x)

√7.0 = √(1-2x)² / √x²

2.65 = 1-2x / x

x = 0.215 atm

Pressure of BrCl @ equilibrium = 1 - 0.43 = 0.570 atm

Pressure of Br₂ and Cl₂ = 0.215 atm

Check:

Kp = (0.570)² / (0.215)²

Kp = 7.0 (check)