How Do You Determine if a Reaction Has Reached Equilibrium Using Kp?

[Phyzwizz]

Ok so I don't know what to do to find out whether the reaction has reached equilibrium or not because I wasn't sure whether the relationship between the equilibrium constant and the reaction quotient is the same for the equilibrium partial pressures(Kp)

N₂(g) + 3H₂(g) <----> 2NH₃(g)

P_NH3 = 3.1 X 10^-2 atm
P_N2 = 8.5 X 10^-1 atm
P_H2 = 3.1 X 10^-3 atm

I calculated the Kp value for these pressures to be 3.8 X 10⁴

The problem next says: If P_N2 = 0.525 atm, P_NH3 = 0.0167 atm ,and P_H2 = 0.00761 atm, does this represent a system at equilibrium.

I calculated the Kp value for these and got 1.2 X 10³

So do I next find the reaction quotient and compare the 2nd Kp value to that in order to find out whether the second set of values reaches equilibrium or not.

PLEASE HELP I'M SORRY FOR ALL THE WRITING

 

[Borek]

I wasn't sure whether the relationship between the equilibrium constant and the reaction quotient is the same for the equilibrium partial pressures(Kp)

Yes, it is the same as between concentrations and K_c.