The formation of SO3 from SO2 and O2 is an intermediate step in the manufacture of sulfuric acid, and it is also responsible for the acid rain phenomenon. The equilibrium constant KP for the reaction
2SO2(g) + O2(g) ⇌ 2SO3(g)
is 0.13 at 803°C. In one experiment, 2.00 mol SO2 and 2.00 mol O2 were initially present in a flask. What must be the total pressure at equilibrium in order to have an 80.0% yield of SO3?