Question

Please help me with this question
For the system, (the previous post i forgot to post the Kp)
PCl5 (g) --> PCl3 (g) + Cl2 (g)
In a 5.0 L flask, the gaseous mixture consists of all three gasses with partial pressures as follows:
PCl5 = 0.012 atm
PCl3 = 0.90 atm
Cl2 = 0.45 atm
Kp = 26 @300 C degree
Is the system at equilibrium?
If yes, explain. If no, which way will the system shift to establish equilibrium?

Answer 1

It's a good thing you have provided the equilibrium constant Kp for that reaction. I was not able to find it.

If the mixture were at equilibrium, you would have
Pcl3*Pcl2/Ppcl5 = 26
In this case, that ratio is
.9*.45/.012 = 33.8
There are more products than there would be at equilibrum, so the reaction will favor the reverse direction.

Answer 2

28