Chapter 15, Problem 5PS

A mixture of SO₂, O₂, and SO₃ at 1000 K contains the gases at the following concentrations: [SO₂] = 5.0 × 10⁻³ mol/L, [O₂] = 1.9 × 10⁻³ mol/L, and [SO₃] = 6.9 × 10⁻³ mol/L. Is the reaction at equilibrium? If not, which way will the reaction proceed to reach equilibrium?

2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g) K_c = 279