In a 2-liter vessel, the reaction 2SO₂ + O₂ ⇄ 2SO₃ reached equilibrium. The initial amounts were 4 mol SO₂ and 2 mol O₂. If 2 mol of SO₃ was present at equilibrium, find the equilibrium constant Kc.
- 1
- 2
- 4
- 0.5
📝 Detailed explanation
Equilibrium SO₃ = 2 mol.SO₂ used = 2 mol, O₂ used = 1 mol.
Equilibrium SO₂ = 4 - 2 = 2 mol; [SO₂] = 1 M.
Equilibrium O₂ = 2 - 1 = 1 mol; [O₂] = 0.5 M.
Equilibrium [SO₃] = 2 / 2 = 1 M.
Kc = [SO₃]² / ([SO₂]² × [O₂]) = 1² / (1² × 0.5) = 2.