What is the equilibrium partial pressure of SO3 in the mixture?

Question

At 900 K the following reaction has Kp = 0.345: 2SO2(g) O2 (g) <==> 2SO3(g) In an equilibrium mixture the partial pressures of SO2 and O2 are 0.165 atm and 0.757 atm, respectively.

Answer 1

The equilibrium constant is,

Kp = [SO3]^2 / [SO2]^2 [O2] = .345

The [ ] indicates concentration.  You use partial pressure in this case because they are gases.  Just plug in the numbers and solve.

Edit:  the / means divide.  the last two [ ] terms are the denominator.