2Cu + O₂ = 2CuO
CuO + 2HCl = CuCl₂ + H₂O
CaCO₃ = CaO + CO₂ (t)
CaO + CO₂ = CaCO₃
CaCO₃ + 2HCl = CaCl₂ + H₂O + CO₂
CO₂ + Ba(OH)₂ = BaCO₃ + H₂O
C + O₂ = CO₂
CO₂ + C = 2CO (t)
2CO + O₂ = 2CO₂
CO₂ + Ca(OH)₂ = CaCO₃ + H₂O
CaCO₃ = CaO + CO₂ (t)
CaO + H₂O = Ca(OH)₂
2HNO₃ + P₂O₅ = N₂O₅ + 2HPO₄
N₂O₅ + Ba(OH)₂ = Ba(NO₃)₂ + H₂O
SO2 -> SO3 -> H2SO4 -> BaSO4
2SO₂ + O₂ = 2SO₃
SO₃ + H₂O = H₂SO₄
H₂SO₄ + Ba(OH)₂ = BaSO₄ + 2H₂O