Chapter 14, Problem 14.33QP

In the contact process, sulfuric acid is manufactured by first oxidizing SO₂ to SO₃, which is then reacted with water The reaction of SO₂ with O₂ is

$2{\text{SO}}_2(g)+{\text{O}}_2\stackrel{}{\rightleftharpoons }2{\text{SO}}_3(g)$

A 2.000-L flask was filled with 0.0400 mol SO₂ and 0.0200 mol O₂. At equilibrium at 900 K_, the flask contained 0.0296 mol SO₃ How many moles of each substance were in the flask at equilibrium?