1. S + H₂ = H₂S ↑
2. 2H₂S↑ + 3O₂↑ = 2SO₂↑ + 2H₂O
3. SO₂↑ + Na₂CO₃ = CO₂↑ + Na₂SO₃
SO₂ + 2Na + CO₃ = CO₂↑ + 2Na + SO₃
SO₂ + CO₃ = CO₂↑ + SO₃
4. Na₂SO₃ + BaCl₂ = BaSO₃↓ + 2NaCl
2Na + SO3 + Ba + 2Cl = BaSO₃↓ + 2Na + 2Cl
SO₃ + Ba = BaSO₃↓
5. BaSO₃↓ + 2HCl = BaCl₂ + H₂O + SO₂↑
BaSO₃↓ + 2H + 2Cl = Ba + 2Cl + H₂O + SO₂↑
BaSO₃↓ + 2H = Ba + H₂O + SO₂↑