PH3---P2O5---CO2---Na2CO3---NaHCO3---Na2CO3--- NaOH---NaHSO4---Na2SO4
2PH₃+4O₂=P₂O₅+3H₂O 2P₂O₅+5C=4P+5CO₂ CO₂+Na₂O=Na₂CO₃ Na₂CO₃+H₂O+CO₂=2NaHCO₃ 2NaHCO₃=t=Na₂CO₃+H₂O+CO₂ Na₂CO₃+Ba(OH)₂=2NaOH+BaCO₃ NaOH+H₂SO₄=NaHSO₄+H₂O NaHSO₄+NaOH=Na₂SO₄+H₂O