Question

Calculate the partial pressure of phosgene that is in equilibrium with a mixture of 0. 025 atm of carbon monoxide and 0. 003 5 atm of chlorine at 600°c.

Answer 1

According to the reaction equation:
by using ICE table:
              CO(g)      + Cl2(g) ↔ COCl2(g)
initial    0.025        0.0035          0
change -X                 -X                +X
Equ     (0.025-X)    (0.0035-X)        X

when:
Kp = P(COCl2)/P(CO}*P(Cl2)      when Kp= 0.2
by substitution:
0.2 = X / (0.025-X)(0.0035-X) by solving this equation for X
∴ X = 1.74x10^-5