1) 4HNO₃ + Cu = 2NO₂ + Cu(NO₃)₂ + 2H₂O.
2) 4NO₂ + O₂ + 2H₂O = 4HNO₃
3) HNO₃ + KOH = KNO₃ + H₂O
4) KNO₃ + Pb = KNO₂ + PbO.
1) 4P + 5O₂ = 2P₂O₅
2) P₂O₅ + 3H₂O = 2H₃PO₄
3) 2H₃PO4 + 3CaCl₂ = Ca₃(PO₄)₂ + 6HCl
1) CaO + 3C = CaC₂ + CO
2) CaC₂ + 2H₂O = C₂H₂ + Ca(OH)₂
3) 2C₂H₂ + 5O₂ = 4CO₂ + 2H₂O