Calculate Kc, please show me steps also and explain if possible?

The general equation when given Kc and/ or Kp is Kp=Kc(RT)^∆n. This equation is derived from the ideal gas law. For this reaction, you want to solve for Kc, so rearrange the equation to be Kc=Kp/(RT)^∆n. Then just plug; so Kc= (34.5)/(.0821)(303)^-1. [By the way, to get ∆n, take the number of moles of products (1) and subtract it by the moles of reactants (2) [1-3=-1]]