Осуществите превращения по схемам:
Cu -> CuO -> CuCl2
CaCO3 ->CaO -> CaCO3 -> CO2 -> BaCO3
C -> CO2 -> CO -> CO2 -> CaCO3 -> CaO -> Ca(OH)2
HNO3 -> N2O5 -> Ba(NO3)2
SO2 -> SO3 -> H2SO4 -> BaSO4

2Cu + O₂ = 2CuOCuO + 2HCl = CuCl₂ + H₂OCaCO₃ = CaO + CO₂ (t)CaO + CO₂ = CaCO₃CaCO₃ + 2HCl = CaCl₂ + H₂O + CO₂CO₂  + Ba(OH)₂ = BaCO₃ + H₂OC + O₂ = CO₂CO₂ + C = 2CO (t)2CO + O₂ = 2CO₂CO₂ + Ca(OH)₂ = CaCO₃ + H₂OCaCO₃ = CaO + CO₂ (t)CaO + H₂O = Ca(OH)₂2HNO₃  + P₂O₅ = N₂O₅ + 2HPO₄  N₂O₅ + Ba(OH)₂ = Ba(NO₃)₂ + H₂OSO2 -> SO3 -> H2SO4 -> BaSO42SO₂ + O₂ = 2SO₃SO₃ + H₂O = H₂SO₄H₂SO₄ + Ba(OH)₂ = BaSO₄ + 2H₂O