Chapter 15, Problem 15.107QP

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 ram phenomenon. The equilibrium constant K_p for the reaction

${\text{2SO}}_{\text{2}}\left(g\right)+{\text{O}}_{\text{2}}\left(g\right)\rightleftarrows {\text{2SO}}_{\text{3}}\left(g\right)$

is 0.13 at 830^°C. In one experiment, 2.00 mol SO₂ and 2.00 mol O₂ were initially present in a flask. What must the total pressure at equilibrium be to have an 80.0% yield of SO₃?