In the reaction 2 SO₂(g) + O₂(g) ⇌ 2 SO₃(g), 0.455 mol SO₂, 0.183 mol O₂, and 0.568 mol SO₃ are introduced simultaneously into a 1.90 L vessel at 1000 K.

(a) If Kc = 2.8 x 10², is this mixture at equilibrium?

(b) If not, in which direction will a net change occur?