Question

The system described by the reaction
CO(g)+Cl2(g)⇌COCl2(g)
is at equilibrium at a given temperature when PCO= 0.31 atm , PCl2= 0.12 atm , and PCOCl2= 0.58 atm . An additional pressure of Cl2(g)= 0.38 atm is added.

Find the pressure of CO when the system returns to equilibrium.

Please show all steps. Thank you

Answer 1

Kp = [COCl2] / [CO][Cl2]

Kp =0.58 / 0.31 x 0.12

Kp = 15.59

PCO = 0.31 atm

PCl2 = 0.12 + 0.38 = 0.50

PCOCl2 = 0.58 atm

on addition of Cl2 equalibrium will shift to the right then

PCO = 0.31 -x

PCl2 = 0.50 - x

PCOCl2 = 0.58 + x

new equailbirium

Kp = ( 0.58 + x) / (0.50 - x)(0.31 -x)

15.59 = ( 0.58 + x ) / 0.155 - 0.50 x - 0.31 x + x^2

15.59 x^2 -12.63 x + 2.42 = 0.58 + x

15.59 x^2 -13.63 x + 1.836 = 0

x = 0.708 or x =0.166

so we shoud take x = 0.166

CO pressure = PCO = 0.31 -x

PCO = 0.31 - 0.166 = 0.144 atm

PCO = 0.144 atm