ve will mainly use HNO2 as an oxidant, but in base medium, HNO2 will be used as a reductant NO2+Fe+2H→NO↑+Fe”+H2O 2NO2+2I+4H→2NO↑+I2+2H2O 5N02+2MnO4+6H-5NO3+2Mn++3H,O 3.The properties of nitric acid and nitrates 1)The structure of nitric acid o①④Ao Na④A-甲一Q④独 ①O④ 2)The structure of NO ④o Q④④ ①①①→m ①O ①O 3)The properties of HNO 3 Pure HNO, is a colorless liquid, can mix with water in any proportion BHNO, is a strong monoacid and volatile 34HNO3skg4NO2↑+O2↑+2HO HNO3 is a strong oxidant A)HNO reacts with nonmetals 3C+4HNO3( dilute)→3CO2↑+2H2O+4NO↑ C+4 HNO3(strong)→CO2↑+2H2O+4NO2↑ S→H2SO4,P→→H3PO42I2→HO3 B)HNO3 reacts with metals; the products will be decided by the concentration of HNO, and the 第6页 2006-02-22
第 6 页 2006-02-22 6 So in acid medium, we will mainly use HNO2 as an oxidant, but in base medium, HNO2 will be used as a reductant NO2 - +Fe2++2H+ →NO↑+Fe3++H2O 2NO2 - +2I- +4H+ →2NO↑+I2+2H2O 5NO2 - +2MnO4 - +6H+ →5NO3 - +2Mn2++3H2O 3.The properties of nitric acid and nitrates 1) The structure of nitric acid 2) The structure of NO3 - 3) The properties of HNO3 ○ 1 Pure HNO3 is a colorless liquid, can mix with water in any proportion ○ 2HNO3 is a strong monoacid and volatile ○ 34HNO3 Δ ⎯or ⎯⎯light → 4NO2↑ + O2↑ + 2H2O ○ 4 HNO3 is a strong oxidant A) HNO3 reacts with nonmetals 3C+4HNO3(dilute)→3CO2↑+2H2O+4NO↑ C+4HNO3(strong)→CO2↑+2H2O+4NO2↑ S→H2SO4, P→H3PO4, I2→HIO3 B) HNO3 reacts with metals; the products will be decided by the concentration of HNO3 and the
strength of reduct A HNO, (strong)+metal-NO Cu+4HNO3 (strong)Cu(NO3)2+2NO21+2H2O Zn+4HNO3(strong)Zn(NO3)+2NO21+2H20 AHNO (dilute)+ active metal-N20 HNO (dilute)+ inactive metal - NO 3Cu+8HNO( dilute)→3Cu(NO3)2+2NO↑+4H2O 4Zn+10HNO (dilute)4Zn(NO 3)2+N201+5H2O HNO3 (very dilute)+ active metal NH; NH4 4Zn+ 10HNO3(very dilute)- 4Zn (NO3)2+ NH4NO3 + 3H2O 6 Nitration 4) The properties of nitrates (1)Nitrates of active metals(Mg) nitrites+O2↑ NaNo NaNO2+O2↑ (2)Nitrates of metals(MgMC metallic oxide+NO2↑+O2↑ 2Pb(NO3)2 2PbO+4NO2↑+O2↑ 2Cu(NO3)2 CuO+4NO2↑+O2↑ (3)Nitrates of inactive metals(<Cu)-> metal NO2t+O2t 2AgNO3->2Ag+2NO2↑+O2↑ (4)Identification of NO 3Fe +NO3 +4H=3Fe +NO+ 2H20 NO+ FesO4=[Fe(NO)SO4 第7页 2006-02-22
第 7 页 2006-02-22 7 strength of reductant △1 HNO3 (strong) + metal → NO2 Cu+4HNO3(strong)→Cu(NO3)2+2NO2↑+2H2O Zn+4HNO3(strong)→Zn(NO3)2+2NO2↑+2H2O △2 HNO3(dilute) + active metal → N2O HNO3(dilute) + inactive metal → NO 3Cu+8HNO3(dilute)→3Cu(NO3)2+2NO↑+4H2O 4Zn+10HNO3(dilute)→4Zn(NO3)2+N2O↑+5H2O △3 HNO3 (very dilute) + active metal → NH3→ + H NH4 + 4Zn + 10HNO3 (very dilute) → 4Zn(NO3)2 + NH4NO3 + 3H2O ○ 5 Nitration 4) The properties of nitrates: (1) Nitrates of active metals (>Mg) →Δ nitrites + O2↑ NaNO3 →Δ NaNO2+ O2↑ (2) Nitrates of metals (Mg≥M≥Cu) →Δ metallic oxide + NO2↑ + O2↑ 2Pb(NO3)2 →Δ 2PbO+ 4NO2↑ + O2↑ 2Cu(NO3)2 →Δ 2CuO+ 4NO2↑ + O2↑ (3) Nitrates of inactive metals (<Cu) →Δ metal + NO2↑ + O2↑ 2AgNO3 →Δ 2Ag+ 2NO2↑ + O2↑ (4) Identification of NO3 - 3Fe2++NO3 - +4H+ =3Fe3++NO+ 2H2O NO + FeSO4 = [Fe(NO)]SO4
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 +OHH2PO4 - ↔ 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
Section Four Main Compounds of arsenic, stibium and bismuth 1. Oxides of arsenic stibium and bismuth 3 As2O white white black 5 As2O5 Sb2O5 white red-brown eparation bM+3O2→2MO 6HNO3+M→HMO3→MO3 (OH)3+Cl2+3NaoH=NaBiO3+2NaCl+3H20 NaBiO3 acid>Bi2Os 2. Hydrates of their oxides H3AsO3 Sb(oh) BI(OH) H3ASO4 H3 SbO NaBiO3 Acidity↑ basicity↑ M*+30H<) M(OH)3=H3MO3 3H*+MO3. AddH: equilibrium+ form M'+ Add H*: equilibrium- form MO3 3. 3. Oxidizing-reducing properties o'(H3AsO//H3AsO3)=0.581V, o(NaBiO3/Bi*)=1.8V Oxidation state Oxidation number Oxidizing properties +3 Reducing properties 2006-02-22
第 9 页 2006-02-22 9 Section Four Main Compounds of arsenic, stibium and bismuth 1. Oxides of arsenic, stibium and bismuth +3 As2O3 Sb2O3 Bi2O3 white white black +5 As2O5 Sb2O5 Bi2O5 white red red-brown Preparation: ○ 14M + 3O2→ 2M2O3 ○ 2HNO3 +M→HMO3→M2O5 Bi(OH)3+Cl2+3NaOH=NaBiO3+2NaCl+3H2O NaBiO3→acid Bi2O5 2. Hydrates of their oxides +3 H3AsO3 Sb(OH)3 Bi(OH)3 +5 H3AsO4 H3 SbO4 NaBiO3 Acidity↑ basicity↑ M3++3OH- ⇔ M(OH)3≡H3MO3⇔ 3H+ +MO3 3- Add H+ : equilibrium ← form M3+ Add H+ : equilibrium → form MO3 3- 3. Oxidizing-reducing properties φø (H3AsO4/H3AsO3)=0.581V, φø (NaBiO3/Bi3+)=1.8V Oxidation state Oxidation number As→Bi +5 Oxidizing properties↑ +3 Reducing properties↓
oH<0.5 (H3ASO4/H3ASO3P(I2 oH>1.0 ((H3AsO4/H3AsO3K <12/ ASO3+I OH 2Mn+NaBiO3+14H=2MnO4 +5Bi+5Na +7H2O 4. Salts of arsenic, stibium and bismuth 1) Hydrolysis of chlorides AsCl3+3H20=H3AsO3+3HCI SbCl3+ H20=SbOC1_+2HCI BiCl3+ H2o=BiOCl]+2HCI O3)3, Sb(SO4)3 2)Sulfides and color Oxidation number Substance Ⅲ As2S Sb2s3 BiS C olor orange red black V Colo yellow orange red solubility Sulfide H2o Dilute HCI Strong HCl NaOH/Na2S or (NH4)2S Dissolve Dissolve Sbs Dissolve Dissolve Dissolve Sbs DissolveDissolve Dissolve 第10页 2006-02-22
第 10 页 2006-02-22 10 pH<0.5 φø (H3AsO4/H3AsO3)>φø I2/IpH>1.0 φø (H3AsO4/H3AsO3)<φø I2/IH3AsO4+2I- +2H+ H3 AsO3+I2+H2O 2Mn2++NaBiO3+14H+ =2MnO4 - +5Bi3++5Na+ +7H2O 4. Salts of arsenic, stibium and bismuth 1) Hydrolysis of chlorides AsCl3+3H2O=H3AsO3+3HCl SbCl3+ H2O=SbOCl↓+2HCl BiCl3+ H2O=BiOCl↓+2HCl Sb(NO3)3, Sb(SO4)3 2) Sulfides ○ 1Type and color Oxidation number Substance Ⅲ As2S3 Sb2S3 Bi2S3 Color yellow orange red black Ⅴ As2S5 Sb2S5 Color yellow orange red ○ 2Solubility Sulfide H2O Dilute HCl Strong HCl NaOH Na2S or (NH4)2S As2S3 – – – Dissolve Dissolve As2S5 – – – Dissolve Dissolve Sb2S3 – – Dissolve Dissolve Dissolve Sb2S5 – – Dissolve Dissolve Dissolve H+ OH-