无机化学双语教学 备课资料 2006年2月 第1页 2006-02-22
第 1 页 2006-02-22 1 无机化学双语教学 备课资料 2006 年 2 月
Chapter One Nitrogen Family(Group V) Central contents 1. Know the general properties of elements of the nitrogen group and inert electron pair effect 2. Know the reactions of ammonia, understand the thermal decomposition trend of ammonium salts 3. Know the properties of nitrous acid and nitrites; understand the structure of nitric acid and nitrate radical; understand the thermal decomposition trend of nitrates 4. Know well the properties of phosphoric acid and phosphates 5. Know the properties of oxides of As, Sb, Bi and their hydrates; understand the properties of sulfides ofAs, Sb, Bi, know the trends of these compounds 6. Understand the properties of the salts of As, Sb, Bi 7. Understand the identification methods for NH4. NO2:. NO3. PO4and Bi'+ 第2页 2006-02-22
第 2 页 2006-02-22 2 Chapter One Nitrogen Family (Group Ⅴ) Central contents: 1. Know the general properties of elements of the nitrogen group and inert electron pair effect 2. Know the reactions of ammonia, understand the thermal decomposition trend of ammonium salts 3. Know the properties of nitrous acid and nitrites; understand the structure of nitric acid and nitrate radical; understand the thermal decomposition trend of nitrates 4. Know well the properties of phosphoric acid and phosphates 5. Know the properties of oxides of As, Sb, Bi and their hydrates; understand the properties of sulfides of As, Sb, Bi; know the trends of these compounds 6. Understand the properties of the salts of As, Sb, Bi 7. Understand the identification methods for NH4 + , NO2 - , NO3 - , PO4 3- and Bi3+
Section One The general Properties of Elements of the Nitrogen Group 1. Know the following 1) Valence shell configuration nsn 2) Nonmetal→ metalloid→ metal 3) Oxidation number:0、+3、+5 4) Bonding character 2. Inert electron pair effect: the same group, the stability will increase from up to down when the elements have lower oxidation number; but the stability will decrease from up to down when the elements have higher oxidation number 第3页 2006-02-22
第 3 页 2006-02-22 3 Section One The General Properties of Elements of the Nitrogen Group 1. Know the following: 1) Valence shell configuration ns2 np3 2) Nonmetal → metalloid → metal 3) Oxidation number: 0、+3、+5 4) Bonding character 2. Inert electron pair effect: In the same group, the stability will increase from up to down when the elements have lower oxidation number; but the stability will decrease from up to down when the elements have higher oxidation number
Section Two Nitrogen and Its main Compounds IThe properties of ammonia and ammonium salts 1)Physical properties of ammonia (1)Ammonia is a colorless gas with an exceedingly pungent ordor 2)Readily soluble in the water, one volume H2O can dissolve seven hundred volumes NH3 (15mol.L-) (3)It condenses to a liquid at-33C at ambient pressure(25C/9.9 atm (4) When liquid ammonia becomes gas, it will absorb a great deal of heat, so we can use it as a refrigeration reagent (5)Liquid ammonia is in some ways similar to liquid water. Salts dissolve in ammonia to form conducting solutions, but solubilities are usually lower in ammonia than in water. Alkali metals dissolve in liquid ammonia, and the solution is called liquid ammonia solution 2)Chemical properties of ammonia (1)Addition reaction: H, M", molecules NH3+H→NH4 4NH3+Cu2→[Cu(NH3]2 2NH3+Ag→[Ag(NH3)2] 8NH3+ CaCl2-CaCI2 8NH3 (2)Substitution reaction: One hydrogen atom is replaced: NaNH2; two hydrogen atoms are replaced: Ag2NH; three hydrogen atoms are replaced Li3N (3)Oxidation reaction: O2, MXOy, X2 400 4NH3+ 30 2N2↑+6H2O 800CP 4NH3+5O2 4NO↑+6H2O 2NH3+3Cu0 4 3Cu+N2↑+3H2O 2NH3+3Cl2→N2↑+6HCl 3)The properties of ammonium salts Ions NH4 rb- r/ Dm 143 133 148 95 第4页 2006-02-22
第 4 页 2006-02-22 4 Section Two Nitrogen and Its main Compounds 1.The properties of ammonia and ammonium salts 1) Physical properties of ammonia: (1) Ammonia is a colorless gas with an exceedingly pungent ordor (2) Readily soluble in the water, one volume H2O can dissolve seven hundred volumes NH3 (15mol·L-1) (3) It condenses to a liquid at -33 ℃ at ambient pressure (25℃/9.9 atm) (4) When liquid ammonia becomes gas, it will absorb a great deal of heat, so we can use it as a refrigeration reagent (5) Liquid ammonia is in some ways similar to liquid water. Salts dissolve in ammonia to form conducting solutions, but solubilities are usually lower in ammonia than in water. Alkali metals dissolve in liquid ammonia, and the solution is called liquid ammonia solution 2) Chemical properties of ammonia: (1)Addition reaction: H+ , Mn+, molecules NH3 + H+ → NH4 + 4NH3 + Cu2+ → [Cu(NH3)4] 2+ 2NH3 + Ag+ → [Ag(NH3)2] + 8NH3 + CaCl2 →CaCl2·8NH3 (2) Substitution reaction: One hydrogen atom is replaced: NaNH2; two hydrogen atoms are replaced: Ag2NH; three hydrogen atoms are replaced: Li3N (3) Oxidation reaction: O2, MxOy, X2 4NH3 + 3O2→C0 400 2N2↑ + 6H2O 4NH3 + 5O2 ⎯⎯C ⎯⎯Pt− →Rh 0 800 4NO↑ + 6H2O 2NH3+3CuO →Δ 3Cu +N2↑ +3H2O 2NH3 + 3Cl2 → N2↑ + 6HCl 3) The properties of ammonium salts Ions NH4 + K+ Rb+ Na+ r + /pm 143 133 148 95
a)Ammonium salts of non-oxidative volatile acid NH3↑+ corresponding acid↑ NH3↑+HC↑ NH4HCO NH3↑+CO2↑+H2O b)Ammonium salts of non-oxidative involatile acid NH3ftacid or acid ammonium salt (H4)3PO4 3NH3↑+H3PO4 (NH4)2SO4 NH3↑+NH4HSO4 c) Ammonium salts of oxidative acid N2t+ h2O or N201+ H20 N,O: laughing gas (NH4)2 Cr2O7 N2↑+Cr2O3+4H2O NHANO N2↑+2H2O 210 NHgNO3 N2O↑+2H2O 2NHANO 2N2↑+O2↑+4H2O d) Identification of NH4 3 NHA+OHA> H2O+NH3↑ NH4+Nessler' s reagent red-brown 2.The properties of nitrous acid and nitrites: DHNO2 is a weak acid, Ka=7.2x10 2)The pure acid is unknown, even aqueous solutions of nitrous acid are unstable, decomposing when heated according to the reaction NO2+H→HNO2→N23bue)+H2O NO↑+NO2↑ 3)Most nitrites are soluble in water except AgNO2, and are poisonous and carcinogenic 4)Oxidizing-reducing properties EA: NO: 0.94 HNO2 0.996 NO NO3001NO2-046NO 第5页 2006-02-22
第 5 页 2006-02-22 5 a) Ammonium salts of non-oxidative volatile acid→Δ NH3↑+ corresponding acid↑ NH4Cl→Δ NH3↑ + HCl↑ NH4HCO3→Δ NH3↑ + CO2↑ + H2O b) Ammonium salts of non-oxidative involatile acid→Δ NH3↑+acid or acid ammonium salt (NH4)3PO4→Δ 3NH3↑ + H3PO4 (NH4)2SO4→Δ NH3↑ + NH4HSO4 c) Ammonium salts of oxidative acid →Δ N2↑+ H2O or N2O↑+ H2O N2O: laughing gas (NH4)2Cr2O7 →Δ N2↑ + Cr2O3 + 4H2O NH4NO2 →Δ N2↑+ 2H2O NH4NO3 about ⎯⎯⎯→C 0 210 N2O↑+ 2H2O 2NH4NO3 > ⎯⎯→C 0 300 2N2↑ + O2↑ + 4H2O d) Identification of NH4 + ○ 1 NH4 + + OH- →Δ H2O +NH3↑ ○ 2NH4 + +Nessler’s reagent→Δ red-brown↓ 2.The properties of nitrous acid and nitrites: 1)HNO2 is a weak acid, Ka θ =7.2×10-4 2) The pure acid is unknown, even aqueous solutions of nitrous acid are unstable, decomposing when heated according to the reaction: NO2 - +H+ →HNO2→N2O3(blue)+H2O NO↑+NO2↑ 3) Most nitrites are soluble in water except AgNO2, and are poisonous and carcinogenic 4) Oxidizing-reducing properties EA θ : NO3 - 0.94 HNO2 0.996 NO EB θ : NO3 - 0.01 NO2 - -0.46 NO
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( 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↓
oH1.0 ((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 pHφø 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-