a) S + O₂ = SO₂
2SO₂ + O₂ = 2SO₃
SO₃ + H₂O = H₂SO₄
Ba(OH)₂ + H₂SO₄ = BaSO₄ + 2H₂O
б) 2CO + O₂ = 2CO₂
CO₂ + KOH = KHCO₃
KHCO₃ + KOH = K₂CO₃ + H₂O
K₂CO₃ + 2HCl = 2KCl + CO₂ + H₂O
в) Cl₂ + H₂ = 2HCl
2HCl + Mg = MgCl₂ + H₂
MgCl₂ + 2NaOH = 2NaCl + Mg(OH)₂
NaCl + AgNO₃ = NaNO₃ + AgCl