Section Three Main Compounds of Phosphorus 1. Oxyacids of phosphorus Oxidation number Chemical formal Name +5 H3PO4 Phosphoric acid +3 H3PO3 Phosphorous acid +1 H3PO Hypophosphorous acid H3PO4-H2O→→HPO3 metaphosphoric acid 2H3 PO4-H20-H4P2O7 diphosphoric acid 3H3 PO4-2H20-HsP3Olo triphosphoric acid 3H3PO4-3H20-(HPO3)3 trimetaphosphoric acid 4H3 PO4-4H2O-(HPO3)4 tetrametaphosphoric acid Condensation degree of phosphoric acid t acidity t 2. The properties of H3 PO4 3. Preparation of H3PO4 Ca3(PO4)2+H2SO4=2H3 PO4+ CasO4 0O5+3H2O→2H3PO4 4. The properties of phosphates Hydrolysis PO43+H2O台HPO4+OH HPO42+H2O台H2PO4+OH HPO4+PO4+H H2PO4+H2O←HPO4+OH H2PO4←HPO4+H 5. Identification of Po 4": PO4+12MoO42+24H*+3NH+ (NH4) PO4 12MoO3 6H2Ol(yellow +6H2O Ca3(PO4)2+ 2H2SO4+ 4H20-2(CaSO4 2H20)+ Ca(H2PO4) Ca3(PO4)2+4H3PO4-3Ca(H2PO4)2 2006-02-22第 8 页 2006-02-22 8 Section Three Main Compounds of Phosphorus 1. Oxyacids of phosphorus Oxidation number Chemical formal Name +5 H3PO4 Phosphoric acid +3 H3PO3 Phosphorous acid +1 H3PO2 Hypophosphorous acid H3PO4-H2O→HPO3 metaphosphoric acid 2H3PO4-H2O→H4P2O7 diphosphoric acid 3H3PO4-2H2O→H5P3O10 triphosphoric acid 3H3PO4-3H2O→(HPO3)3 trimetaphosphoric acid 4H3PO4-4H2O→(HPO3)4 tetrametaphosphoric acid Condensation degree of phosphoric acid ↑ acidity↑ 2. The properties of H3PO4 3. Preparation of H3PO4 Ca3(PO4)2+H2SO4→2H3PO4+ CaSO4 P2O5 + 3H2O→ 2H3PO4 4. The properties of phosphates 1) Solubility 2) Hydrolysis PO4 3- + H2O ↔ HPO4 2- +OH- HPO4 2- + H2O ↔ H2PO4 - +OH- HPO4 2- ↔ PO4 3- +H+ H2PO4 - + H2O ↔ H3PO4 +OH￾H2PO4 - ↔ HPO4 2- + H+ 5. Identification of PO4 3-: PO4 3-+12MoO4 2-+24H+ +3NH4 + → (NH4)3PO4·12MoO3·6H2O↓(yellow)+6H2O Ca3(PO4)2 + 2H2SO4 + 4H2O →2(CaSO4·2H2O) + Ca(H2PO4)2 Ca3(PO4)2+4H3PO4→3Ca(H2PO4)2