The equilibrium constant, Kp, for the following reaction is 0.497 at 500 K:

PCl5(g) PCl3(g) + Cl2(g)

Calculate the equilibrium partial pressures of all species when PCl5(g) is introduced into an evacuated flask at a pressure of 1.46 atm at 500 K.

PPCl5 = atm
PPCl3 = atm
PCl2 = atm

1 answer

......PCl5 ==> PCl3 + Cl2
I.....1.46......0......0
C.....-p........p......p
E.....1.46-p....p......p

Substitute into the Kp expression and solve for p, then evaluate 1.46-p.