第 1 页 2006-02-22 1 无机化学双语教学 备课资料 2006 年 2 月 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 NH 4 + , NO 2 - , NO 3 - , PO 4 3- and Bi 3+ 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 ns 2 np 3 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 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 H 2 O can dissolve seven hundred volumes NH 3 (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 + , M n+ , molecules NH 3 + H + → NH 4 + 4NH 3 + Cu 2+ → [Cu(NH 3 ) 4 ] 2+ 2NH 3 + Ag + → [Ag(NH 3 ) 2 ] + 8NH 3 + CaCl 2 → CaCl 2 ·8NH 3 (2) Substitution reaction: One hydrogen atom is replaced: NaNH 2 ; two hydrogen atoms are replaced: Ag 2 NH; three hydrogen atoms are replaced: Li 3 N (3) Oxidation reaction: O 2 , M x O y , X 2 4NH 3 + 3O 2 → C 0 400 2N 2 ↑ + 6H 2 O 4NH 3 + 5O 2 ??? →? ?RhPtC 0 800 4NO↑ + 6H 2 O 2NH 3 +3CuO → Δ 3Cu +N 2 ↑ +3H 2 O 2NH 3 + 3Cl 2 → N 2 ↑ + 6HCl 3) The properties of ammonium salts Ions NH 4 + K + Rb + Na + r + /pm 143 133 148 95 第 5 页 2006-02-22 5 a) Ammonium salts of non-oxidative volatile acid → Δ NH 3 ↑+ corresponding acid↑ NH 4 Cl → Δ NH 3 ↑ + HCl↑ NH 4 HCO 3 → Δ NH 3 ↑ + CO 2 ↑ + H 2 O b) Ammonium salts of non-oxidative involatile acid → Δ NH 3 ↑+acid or acid ammonium salt (NH 4 ) 3 PO 4 → Δ 3NH 3 ↑ + H 3 PO 4 (NH 4 ) 2 SO 4 → Δ NH 3 ↑ + NH 4 HSO 4 c) Ammonium salts of oxidative acid → Δ N 2 ↑+ H 2 O or N 2 O↑+ H 2 O N 2 O: laughing gas (NH 4 ) 2 Cr 2 O 7 → Δ N 2 ↑ + Cr 2 O 3 + 4H 2 O NH 4 NO 2 → Δ N 2 ↑+ 2H 2 O NH 4 NO 3 ?? →? Cabout 0 210 N 2 O↑+ 2H 2 O 2NH 4 NO 3 ? →? > C 0 300 2N 2 ↑ + O 2 ↑ + 4H 2 O d) Identification of NH 4 + ○ 1 NH 4 + + OH - → Δ H 2 O +NH 3 ↑ ○ 2 NH 4 + +Nessler’s reagent → Δ red-brown↓ 2.The properties of nitrous acid and nitrites: 1)HNO 2 is a weak acid, K a 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: NO 2 - +H + → HNO 2 → N 2 O 3 (blue)+H 2 O NO↑+NO 2 ↑ 3) Most nitrites are soluble in water except AgNO 2 , and are poisonous and carcinogenic 4) Oxidizing-reducing properties E A θ : NO 3 - 0.94 HNO 2 0.996 NO E B θ : NO 3 - 0.01 NO 2 - -0.46 NO 第 6 页 2006-02-22 6 So in acid medium, we will mainly use HNO 2 as an oxidant, but in base medium, HNO 2 will be used as a reductant NO 2 - +Fe 2+ +2H + → NO↑+Fe 3+ +H 2 O 2NO 2 - +2I - +4H + → 2NO↑+I 2 +2H 2 O 5NO 2 - +2MnO 4 - +6H + → 5NO 3 - +2Mn 2+ +3H 2 O 3.The properties of nitric acid and nitrates 1) The structure of nitric acid 2) The structure of NO 3 - 3) The properties of HNO 3 ○ 1 Pure HNO 3 is a colorless liquid, can mix with water in any proportion ○ 2 HNO 3 is a strong monoacid and volatile ○ 3 4HNO 3 ?? →? Δ lightor 4NO 2 ↑ + O 2 ↑ + 2H 2 O ○ 4 HNO 3 is a strong oxidant A) HNO 3 reacts with nonmetals 3C+4HNO 3 (dilute)→ 3CO 2 ↑+2H 2 O+4NO↑ C+4HNO 3 (strong)→ CO 2 ↑+2H 2 O+4NO 2 ↑ S→ H 2 SO 4 , P→ H 3 PO 4 , I 2 → HIO 3 B) HNO 3 reacts with metals; the products will be decided by the concentration of HNO 3 and the 第 7 页 2006-02-22 7 strength of reductant △ 1 HNO 3 (strong) + metal → NO 2 Cu+4HNO 3 (strong)→ Cu(NO 3 ) 2 +2NO 2 ↑+2H 2 O Zn+4HNO 3 (strong)→ Zn(NO 3 ) 2 +2NO 2 ↑+2H 2 O △ 2 HNO 3 (dilute) + active metal → N 2 O HNO 3 (dilute) + inactive metal → NO 3Cu+8HNO 3 (dilute)→ 3Cu(NO 3 ) 2 +2NO↑+4H 2 O 4Zn+10HNO 3 (dilute)→ 4Zn(NO 3 ) 2 +N 2 O↑+5H 2 O △ 3 HNO 3 (very dilute) + active metal → NH 3→ + H NH 4 + 4Zn + 10HNO 3 (very dilute) → 4Zn(NO 3 ) 2 + NH 4 NO 3 + 3H 2 O ○ 5 Nitration 4) The properties of nitrates: (1) Nitrates of active metals (>Mg) → Δ nitrites + O 2 ↑ NaNO 3 → Δ NaNO 2 + O 2 ↑ (2) Nitrates of metals (Mg≥M≥Cu) → Δ metallic oxide + NO 2 ↑ + O 2 ↑ 2Pb(NO 3 ) 2 → Δ 2PbO+ 4NO 2 ↑ + O 2 ↑ 2Cu(NO 3 ) 2 → Δ 2CuO+ 4NO 2 ↑ + O 2 ↑ (3) Nitrates of inactive metals (<Cu) → Δ metal + NO 2 ↑ + O 2 ↑ 2AgNO 3 → Δ 2Ag+ 2NO 2 ↑ + O 2 ↑ (4) Identification of NO 3 - 3Fe 2+ +NO 3 - +4H + =3Fe 3+ +NO+ 2H 2 O NO + FeSO 4 = [Fe(NO)]SO 4 第 8 页 2006-02-22 8 Section Three Main Compounds of Phosphorus 1. Oxyacids of phosphorus Oxidation number Chemical formal Name +5 H 3 PO 4 Phosphoric acid +3 H 3 PO 3 Phosphorous acid +1 H 3 PO 2 Hypophosphorous acid H 3 PO 4 -H 2 O→ HPO 3 metaphosphoric acid 2H 3 PO 4 -H 2 O→ H 4 P 2 O 7 diphosphoric acid 3H 3 PO 4 -2H 2 O→ H 5 P 3 O 10 triphosphoric acid 3H 3 PO 4 -3H 2 O→ (HPO 3 ) 3 trimetaphosphoric acid 4H 3 PO 4 -4H 2 O→ (HPO 3 ) 4 tetrametaphosphoric acid Condensation degree of phosphoric acid ↑ acidity↑ 2. The properties of H 3 PO 4 3. Preparation of H 3 PO 4 Ca 3 (PO 4 ) 2 +H 2 SO 4 → 2H 3 PO 4 + CaSO 4 P 2 O 5 + 3H 2 O→ 2H 3 PO 4 4. The properties of phosphates 1) Solubility 2) Hydrolysis PO 4 3- + H 2 O ? HPO 4 2- +OH - HPO 4 2- + H 2 O ? H 2 PO 4 - +OH - HPO 4 2- ? PO 4 3- +H + H 2 PO 4 - + H 2 O ? H 3 PO 4 +OH - H 2 PO 4 - ? HPO 4 2- + H + 5. Identification of PO 4 3- : PO 4 3- +12MoO 4 2- +24H + +3NH 4 + → (NH 4 ) 3 PO 4 ·12MoO 3 ·6H 2 O↓(yellow)+6H 2 O Ca 3 (PO 4 ) 2 + 2H 2 SO 4 + 4H 2 O → 2(CaSO 4 ?2H 2 O) + Ca(H 2 PO 4 ) 2 Ca 3 (PO 4 ) 2 +4H 3 PO 4 → 3Ca(H 2 PO 4 ) 2 第 9 页 2006-02-22 9 Section Four Main Compounds of arsenic, stibium and bismuth 1. Oxides of arsenic, stibium and bismuth +3 As 2 O 3 Sb 2 O 3 Bi 2 O 3 white white black +5 As 2 O 5 Sb 2 O 5 Bi 2 O 5 white red red-brown Preparation: ○ 1 4M + 3O 2 → 2M 2 O 3 ○ 2 HNO 3 +M→ HMO 3 → M 2 O 5 Bi(OH) 3 +Cl 2 +3NaOH=NaBiO 3 +2NaCl+3H 2 O NaBiO 3→ acid Bi 2 O 5 2. Hydrates of their oxides +3 H 3 AsO 3 Sb(OH) 3 Bi(OH) 3 +5 H 3 AsO 4 H 3 SbO 4 NaBiO 3 Acidity↑ basicity↑ M 3+ +3OH - ? M(OH) 3 ≡H 3 MO 3? 3H + +MO 3 3- Add H + : equilibrium ← form M 3+ Add H + : equilibrium → form MO 3 3- 3. Oxidizing-reducing properties φ ? (H 3 AsO 4 /H 3 AsO 3 )=0.581V, φ ? (NaBiO 3 /Bi 3+ )=1.8V Oxidation state Oxidation number As→ Bi +5 Oxidizing properties↑ +3 Reducing properties↓ 第 10 页 2006-02-22 10 pH<0.5 φ ? (H 3 AsO 4 /H 3 AsO 3 )>φ ? I 2 /I - pH>1.0 φ ? (H 3 AsO 4 /H 3 AsO 3 )<φ ? I 2 /I - H 3 AsO 4 +2I - +2H + H 3 AsO 3 +I 2 +H 2 O 2Mn 2+ +NaBiO 3 +14H + =2MnO 4 - +5Bi 3+ +5Na + +7H 2 O 4. Salts of arsenic, stibium and bismuth 1) Hydrolysis of chlorides AsCl 3 +3H 2 O=H 3 AsO 3 +3HCl SbCl 3 + H 2 O=SbOCl↓+2HCl BiCl 3 + H 2 O=BiOCl↓+2HCl Sb(NO 3 ) 3 , Sb(SO 4 ) 3 2) Sulfides ○ 1 Type and color Oxidation number Substance Ⅲ As 2 S 3 Sb 2 S 3 Bi 2 S 3 Color yellow orange red black Ⅴ As 2 S 5 Sb 2 S 5 Color yellow orange red ○ 2 Solubility Sulfide H 2 O Dilute HCl Strong HCl NaOH Na 2 S or (NH 4 ) 2 S As 2 S 3 – – – Dissolve Dissolve As 2 S 5 – – – Dissolve Dissolve Sb 2 S 3 – – Dissolve Dissolve Dissolve Sb 2 S 5 – – Dissolve Dissolve Dissolve H + OH - 第 11 页 2006-02-22 11 Bi 2 S 3 – – Dissolve – – Acidic/neutral sulfide + basic sulfide → sulfoacid salt Acidic/neutral sulfide + base → oxysalt + sulfoacid salt As 2 S 3 + 3Na 2 S → 2Na 3 AsS 3 As 2 S 3 +6OH - → AsO 3 3- +AsS 3 3- +3H 2 O As 2 S 5 + 3Na 2 S → 2Na 3 AsS 4 4As 2 S 5 +24OH - → 3AsO 4 3- +5AsS 4 3- +12H 2 O 第 12 页 2006-02-22 12 Chapter Two Oxygen Family (Group Ⅵ) Central Contents: 1. Know the general properties of group Ⅵ 2. Understand the structure of ozone and formation of π bond 3. Understand the structure and properties of H 2 O 2 4. Know well the properties of H 2 S, M x S y 5. Understand the properties of the oxyacids of sulfur (H 2 SO 4 , H 2 S 2 O 3 , H 2 S 2 O 7 , H 2 S 2 O 8 ) and their salts 6. Know how to identify S 2- , SO 3 2- , S 2 O 3 2- and SO 4 2- Section One General Properties Element Oxygen (O) Sulfur (S) Selenium (Se) Tellurium (Te) Polonium (Po) Atomic number 8 16 34 52 84 Valence shell electron configuration 2s 2 2p 4 3s 2 3p 4 4s 2 4p 4 5s 2 5p 4 6s 2 6p 4 Atomic radius/pm 66 104 117 137 153 Oxidation number -1,-2,0 -2,0, +4,+6 -2,0,+2, +4,+6 -2,0,+2, +4,+6 - M 6+ 140 184 198 221 - Ionic radius/pm M 2- - 29 42 56 67 First ionization energy I 1 /kJ·mol -1 1314 1000 941 869 812 Electronic affinity E A1 /kJ·mol -1 -141 -200.4 -195 -190.2 -173.7 Electronegativity 3.5 2.5 2.4 2.1 2.0 第 13 页 2006-02-22 13 Oxidation number Type of compounds Examples -2 Normal oxides, oxyacids, oxysalts Na 2 O, CaO, H 2 O -1 Peroxides Na 2 O 2 , BaO 2 , H 2 O 2 -1/2 Hyperoxides KO 2 -1/3 Ozonides KO 3 0 O 2 , O 3 For the following oxides, determine the type: PbO 2 , BaO 2 , SnO 2 , Na 2 O, KO 2 , Na 2 O 2 The properties of peroxides and hyperoxides: 1. React with water or acid: Na 2 O 2 + 2H 2 O = 2NaOH + H 2 O 2 Na 2 O 2 + H 2 SO 4 = Na 2 SO 4 + H 2 O 2 2KO 2 + 2H 2 O = 2KOH + H 2 O 2 + O 2 ↑ 2KO 2 + H 2 SO 4 = K 2 SO 4 + H 2 O 2 + O 2 ↑ 2. React with carbon dioxide 2Na 2 O 2 + 2CO 2 = 2Na 2 CO 3 + O 2 ↑ 2BaO 2 + 2CO 2 = 2BaCO 3 + O 2 ↑ 4KO 2 + 2CO 2 = 2K 2 CO 3 + 3O 2 ↑ Section Two Oxygen, and hydrogen peroxide 1. Ozone :O 3 1) Formation: bond 2) Structure 2. H 2 O 2 (hydrogen peroxide): 1) Structure 2) Properties ○ 1 Pure hydrogen peroxide is a colorless liquid; hydrogen peroxide molecules will associate if they exist in liquid state or solid state because of hydrogen bonds; hydrogen peroxide can dissolve in water in any proportion 第 14 页 2006-02-22 14 ○ 2 Instability: 2H 2 O 2 =2H 2 O+O 2 E A θ O 2 0.695 H 2 O 2 1.76 H 2 O E B θ O 2 -0.076 HO 2 - +0.867 OH - E θ right >E θ left → Disproportionation reaction Factors that affect decomposition of H 2 O 2 : △ 1 Light or heat △ 2 Acid or base (In basic medium, the disproportionation reaction will be fast) △ 3 Impurity: some ions of heavy metals: Mn 2+ , Fe 3+ , Cr 3+ , Cu 2+ or their compounds will accelerate decomposition ○ 3 Oxidizing /reducing properties △ 1 Oxidizing properties H 2 O 2 + 2I - + 2H + = I 2 + 2H 2 O PbS + 4 H 2 O 2 = PbSO 4 + 4H 2 O 2Cr(OH) 4 - +3H 2 O 2 +2OH - =2CrO 4 2- +8H 2 O △ 2 Reducing properties 2MnO 4 - +5H 2 O 2 +6H + =2Mn 2+ +5O 2 ↑+8H 2 O Cl 2 + H 2 O 2 = 2HCl + O 2 5H 2 O 2 + 2HIO 3 = I 2 + 5O 2 ↑ + 6H 2 O 5H 2 O 2 + I 2 = 2HIO 3 + 4H 2 O ○ 4 Weak acid Section Three Sulfur and main compounds of sulfur Oxidation number Type of compounds Examples -2 Sulfides, sulfoacids and the salts Na 2 S, As 2 S 3 , Na 2 SnS 3 -1 Polysulfide Na 2 S 2 0 Simple substance S 8 第 15 页 2006-02-22 15 +2 Thiosulfuric acid Na 2 S 2 O 3 +2.5 Tetrathionic acid Na 2 S 4 O 6 +4 Sulfurous acid Na 2 SO 3 , SO 2 +6 Disulfuric acid, sulfuric acid SO 3 , Na 2 S 2 O 7 +6 Persulfuric acid H 2 S 2 O 8 1. Hydrogen sulfide 1) Colorless gas, stinky poisonous gas CH 3 CSNH 2 +2H 2 O=CH 3 COO - +NH 4 + +H 2 S↑ CH 3 CSNH 2 +2OH - =CH 3 COO - +NH 4 + +S 2- 2) Weak acid 3) Reducing properties 2H 2 S + O 2 = 2S↓ + 2H 2 O 2H 2 S + 3O 2 = 2SO 2 ↑ + 2H 2 O 2Fe 3+ + H 2 S = 2Fe 2+ + S↓ + 2H + H 2 S + I 2 = 2HI + S↓ H 2 S + Cl 2 + 4H 2 O = H 2 SO 4 + 8HCl 5H 2 S+8MnO 4 - +24H + =8Mn 2+ + 5H 2 SO 4 +12 H 2 O 2. Sulfides 1) Solubility: ○ 1 Acid salt: dissolve ○ 2 Normal salt 2) Hydrolysis: ○ 1 S 2- : S 2- + H 2 O ? HS - + OH - ○ 2 Al 2 S 3 , Cr 2 S 3 (Complete hydrolysis) Al 2 S 3 + 6H 2 O = 2Al(OH) 3 ↓ + 3H 2 S↑ Cr 2 S 3 + 6H 2 O = 2Cr(OH) 3 ↓ + 3H 2 S↑ Dissolve Insoluble, but dissolve in following solutions Hydrolysis 第 16 页 2006-02-22 16 Dilute HCl Strong HCl HNO3 Aqua regia AⅠ NH 4 + AⅡ * ZnS MnS FeS CoS * NiS * PbS CdS SnS SnS 2 Sb 2 S 3 Sb 2 S 5 Bi 2 S 3 Ag 2 S CuS Cu 2 S As 2 S 3 As 2 S 5 CoS NiS HgS Hg 2 S Al 2 S 3 Cr 2 S 3 K sp θ >10 -24 10 -25 ~10 -30 10 -30 ~10 -50 <10 -50 Note AⅡ * : Sparingly soluble 3) Reducing properties 3. Polysulfides 1) Preparation: Na 2 S + (x-1)S = Na 2 S x S 2- + (x-1)S = S x 2- (x:2~6) x↑ color↑ yellow → orangish yellow→ red 2) Properties ○ 1 Instability: S 2 2- + 2H + = H 2 S 2 → H 2 S+S↓ ○ 2 Oxidizing/reducing properties Oxidizing properties: SnCl 2 S 2- SnS↓ ?2 2 S SnS 3 2- Reducing properties 4FeS 2 (pyrite) + 11O 2 = 2Fe 2 O 3 + 8SO 2 2) Application 3) Section Five Oxyacids and Oxysalts of Sulfur 1. Sulfurous acid and sulfites 第 17 页 2006-02-22 17 1) Sulfurous acid ○ 1 Instability: H 2 SO 3 = H 2 O + SO 2 ○ 2 Acidity: K 1 θ =1.3×10 -2 , K 2 θ =6.2×10 -8 ○ 3 Oxidizing/reducing properties E A θ : SO 4 2- 0.158 H 2 SO 3 0.449 S E B θ : SO 4 2- -0.936 SO 3 2- -0.59 S Reducing properties: △ 1 In acidic medium: I 2 + SO 3 2- + H 2 O = SO 4 2- + 2I - + 2H + 5SO 3 2- +2MnO 4 - +6H + =2Mn 2+ +5SO 4 2- + 3H 2 O 2H 2 SO 3 + O 2 = 2H 2 SO 4 △ 2 In basic medium: SO 3 2- + I 2 + 2OH - = SO 4 2- +2I - + H 2 O Oxidizing properties: H 2 SO 3 + 2H 2 S = 3S↓ + 3H 2 O 2) Sulfites ○ 1 Solubility: Acid salts and some normal salts (K + , Na + , NH 4 + ) will be readily soluble, others will be insoluble CaSO 3 + SO 2 + H 2 O = Ca(HSO 3 ) 2 ○ 2 Thermal stability 4Na 2 SO 3 → Δ 3 Na 2 SO 4 + Na 2 S ○ 3 Reducing properties 2Na 2 SO 3 + O 2 → 2Na 2 SO 4 ○ 4 Identification of SO 3 2- SO 3 2- + 2H + = H 2 SO 3 → SO 2 ↑+ H 2 O The test paper of fuchsine: red → colorless 2. Sulfuric acid and sulfates 第 18 页 2006-02-22 18 1) Sulfuric acid: Structure Properties: Physical properties Chemical properties ○ 1 Strong acid: H 2 SO 4 → H + + HSO 4 - HSO 4 - ? H + + SO 4 2- K 2 θ =1.0×10 -2 ○ 2 Thermal stability H 2 SO 4 → Δ SO 3 + H 2 O ○ 3 Oxidizing properties: △ 1 Sparse sulfuric acid: H + △ 2 Concentrated sulfuric acid: ◇ 1 Reacts with many metals and nonmetals: Cu+2H 2 SO 4 (strong)=CuSO 4 +SO 2 ↑+2H 2 O C+2H 2 SO 4 (strong)=CO 2 ↑+SO 2 ↑+2H 2 O S+2H 2 SO 4 (strong)=3SO 2 ↑+2H 2 O ◇ 2 Reacts with active metals: Zn+2H 2 SO 4 (strong)=ZnSO 4 +SO 2 ↑+2H 2 O 3Zn+4H 2 SO 4 (strong)=3ZnSO 4 +S+4H 2 O 4Zn+5H 2 SO 4 (strong)=4ZnSO 4 + H 2 S↑+4H 2 O ◇ 3 Passivation: Fe, Al, Cr ○4 Water absorption: strong, H 2 SO 4 can dissolve in water in any proportion 第 19 页 2006-02-22 19 -H 2 O △1 If we mix H 2 SO 4 and H 2 O, we get a lot of heat △ 2 H 2 SO 4 is a kind of dryer: Cl 2 , CO 2 △ 3 H 2 SO 4 can be used as dehydrater in organic reactions 2) Sulfates ○ 1 Solubility: Acid salts and the great number of normal salts will be readily soluble, few will be insoluble just like BaSO 4 , PbSO 4 and Ag 2 SO 4 ○ 2 When soluble salts precipitate out of solution, the salts will contain crystal water (crystalline hydrate): CuSO 4 ·5H 2 O: bluestone FeSO 4 ·7H 2 O: copperas ○ 3 Thermal stability is determined by the charge, radius and ionic electron configuration of corresponding cation (ionic polarization) △ 1 Cation electron configuration: 8 K 2 SO 4 , Na 2 SO 4 , BaSO 4 : stable △ 2 Cation electron configuration: 18, 18+2, 9~17 CuSO 4 , Ag 2 SO 4 , PbSO 4 , Fe 2 (SO 4 ) 3 : unstable 3. Disulfuric acid and pyrosulfates 1) Disulfuric acid: H 2 S 2 O 7 If we cool oleum, we can get disulfuric acid SO 3 + H 2 SO 4 = H 2 S 2 O 7 (colorless) 2H 2 SO 4 H 2 S 2 O 7 H 2 S 2 O 7 + H 2 O → 2H 2 SO 4 2) Pyrosulfates ○ 1 Preparation: 2KHSO 4 → Δ K 2 S 2 O 7 + H 2 O ○ 2 K 2 S 2 O 7 → Δ K 2 SO 4 + SO 3 ○ 3 Al 2 O 3 +3K 2 S 2 O 7 → Δ Al 2 (SO 4 ) 3 +3 K 2 SO 4 第 20 页 2006-02-22 20 Cr 2 O 3 +3K 2 S 2 O 7 → Δ Cr 2 (SO 4 ) 3 +3 K 2 SO 4 4. Thiosulfuric acid and thiosulfates 1) Thiosulfuric acid: Thermal instability: H 2 S 2 O 3 → SO 2 ↑+S↓+H 2 O 2) Thiosulfates: Na 2 S 2 O 3 ·5H 2 O: sodium thiosulfate, hypo ○ 1 Preparation: Na 2 SO 3 + S → Δ Na 2 S 2 O 3 ○ 2 S 2 O 3 2- is stable in neutral or basic medium, if we add acid to solution, the following reaction will occur: S 2 O 3 2- + 2H + =H 2 S 2 O 3 → SO 2 ↑+S↓+H 2 O ○ 3 Reducing properties S 2 O 3 2- + I 2 = S 4 O 6 2- + 2I - S 2 O 3 2- +4Cl 2 +5H 2 O=2SO 4 2- +8Cl - +10H + ○ 4 AgCl+2S 2 O 3 2- =[Ag(S 2 O 3 ) 2 ] 3- +Cl - AgBr+2S 2 O 3 2- =[Ag(S 2 O 3 ) 2 ] 3- +Br - ○ 5 Identification Add acid: S 2 O 3 2- + 2H + → SO 2 ↑+S↓+H 2 O Add AgNO 3 : 2Ag + +S 2 O 3 2- → Ag 2 S 2 O 3 ↓ Ag 2 S 2 O 3 +H 2 O→ Ag 2 S↓+H 2 SO 4 White-yellow-orange-brown-black 5. Persulfuric acid and persulfates 1) Persulfuric acid ○ 1 Structure ○ 2 Preparation: electrolyze NH 4 HSO 4 Anode: 2SO 4 2- - 2e = S 2 O 8 2- Cathode: 2H + + 2e = H 2 2HSO 4 - S 2 O 8 2- + H 2 2) Persulfates electroly 第 21 页 2006-02-22 21 (NH 4 ) 2 S 2 O 8 +2KHSO 4 =K 2 S 2 O 8 +2NH 4 HSO 4 K 2 S 2 O 8 + H 2 O 2KHSO 4 + H 2 O 2 Oxidizing properties: S 2 O 8 2- + 2e = 2SO 4 2- E θ =1.96v 2Mn 2+ +5S 2 O 8 2- +8H 2 O 2MnO 4 - +10SO 4 2- +16H + 2I - + S 2 O 8 2- I 2 + 2SO 4 2- Thermal instability: 2K 2 S 2 O 8 → Δ 2K 2 SO 4 + O 2 ↑+2SO 3 ↑ Chapter Three Halogens Central Contents: 1. Know preparation methods and general properties of halogens 2.Understand the reducing properties, acidity, stability and trends of halogen acids 3. Understand the properties of halides (bond type and solubility) and their trends 4. Understand oxyacids and oxysalts of chlorine and their trends 5. Know the disproportionation law of X 2 , XO - in basic medium 6. Know the ionization of hydrates (R-O-H rule) 7. Know how to identify of Cl - , Br - and I - Section One General Properties of Halogens Halogens: Fluorine, chlorine, bromine, iodine, astatine 1.Natural occurring forms 1) F:CaF 2 (fluorite),Na 3 AlF 6 (cryolite) 2) Cl, Br, I: Exist in seawater (inorganic salt: Na, K, Ca, Mg) 3) At: Unstable (radioactive) 2. General properties 1) Valence shell configuration:ns 2 np 5 H + Ag + 第 22 页 2006-02-22 22 2) Oxidation number: F: 0, -1 Cl, Br, I: -1, 0, +1, +3, +5, +7 3) Comparing with other families, halogens are most active non-metals, and they have highest electronegative and first ionization energy Element F Cl Br I Atomic number 9 17 35 53 Atomic radius/pm 64 99 114 133 I 1 /kJ?mol -1 1681 1251 1140 1008 E A1 /kJ?mol -1 -327.9 -349 -324.7 -295.1 χ p 4.0 3.0 2.8 2.5 Section Two Elementary Substance of Halogens 1. Physical properties 1) The elements all form diatomic molecules, and when they exist in the solid state, they are molecular crystals 2) They have low melting and boiling points, but the melting and boiling points of the elements increase with increased atomic number. Fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid 3) The halogen molecules are all colored. This is due to the absorption of visible light. The excitation energies follow the same trend as the ionization energies; excitation of the larger iodine atom requires less energy. Gaseous molecules of F 2 absorb violet light (high energy) and therefore appear yellow, whereas gaseous molecules of I 2 absorb yellow light (lower energy) and appear violet Substance F 2 Cl 2 Br 2 I 2 State Gas Gas Liquid Solid Color Pale yellow Olivine Red-brown Purple-black Color Light be absorbed 第 23 页 2006-02-22 23 Color Wavelength Olivine Violet 400-450nm Yellow Blue 450-480nm Orange Greenish blue 480-490nm Red Blue-green 490-500nm Mauve Green 500-560nm Violet Olivine 560-580nm Blue Yellow 580-600nm Greenish blue Orange 600-650nm Blue-green Red 650-750nm E=hν=hc/λ E↑ λ↓ 4) Solubility ○ 1 Cl 2 , Br 2 , I 2 have low solubility in water ○ 2 They are already soluble in some organic solvent like CCl 4 , CS 2 , ethyl ether and benzene ○ 3 I 2 is quite soluble in solution of KI, HI or other iodides: I 2 +I - I 3 - 5) Toxic 6) Dissociation energy Cl 2 → Br 2 → I 2 ↓ 2. Chemical properties 1) Oxidizing properties F 2 → I 2 ↓ ○ 1 E θ (F 2 /F - ) >E θ (Cl 2 /Cl - ) >E θ (Br 2 /Br - ) >E θ (I 2 /I - ) ○ 2 Fluorine is the most reactive of all the elements in the periodic table. It reacts with all the other elements except the lighter noble gases (He, Ne, Ar). Reactions with many elements are vigorous, and often explosive. The reactivity of the other halogens decreases in the order Cl>Br>I. 2) Reactions of the halogens with water ○ 1 Fluorine is such a strong oxidizing agent that it oxidizes water to oxygen. The large negative free energy change indicates a strongly exothermic and spontaneous reaction: 2F 2 +2H 2 O 第 24 页 2006-02-22 24 4HF+O 2 ΔG = -795 kJ·mol -1 The oxidation of water by chlorine is thermodynamically possible, but since the energy of activation is high, this reaction almost never occurs. In fact, another reaction occurs ○ 2 Disproportionation reaction X 2 +H 2 O H + + X - + HXO Substance Cl 2 Br 2 I 2 K θ 4.2×10 -4 7.2×10 -9 2.0×10 -13 Section Three Hydrogen Halides 1. Physical properties 1) Hydrogen halides are colorless gases with penetrating odor; gaseous HF is very toxic 2) They will combine with the water in air to form acid vapor 3) Hydrogen halides are soluble in water 4) Melting and boiling points: HCl→ HBr→ HI ↑ HF is abnormal Substance HF HCl HBr HI Melting point/℃-83.1 -114.8 -88.5 -50.8 Boiling point/℃19.54 -84.9 -67 -35.38 2. Chemical properties 1) Acidity Substance HF HCl HBr HI θ a K 6.3×10 -4 1.74×10 8 1.5×10 10 3.5×10 11 2) Reducing properties: F - → Cl - → Br - → I - ↑ 3) Thermal stability 第 25 页 2006-02-22 25 Substance HF HCl HBr HI D θ (HX,g)/kJ·mol -1 568.6 431.8 365.7 298.7 θ mf HΔ /kJ·mol -1 -271.1 -92.3 -36.4 +26.5 4) Preparation of hydrogen halides HF: CaF 2 +H 2 SO 4 (strong)→ CaSO 4 +2HF↑ HCl:NaCl+H 2 SO 4 (strong)→ NaHSO 4 +HCl↑ HBr: PBr 3 +3H 2 O→ H 3 PO 3 +3HBr↑ or 3Br 2 +2P+6H 2 O → 2H 3 PO 3 +6HBr↑ HI: PBr 3 +3H 2 O→ H 3 PO 3 +3HBr↑ or 3I 2 +2P+6H 2 O → 2H 3 PO 3 +6HI↑ 5) SiO 2 + 4HF→ SiF 4 ↑ + 2H 2 O CaSiO 3 +6HF→ SiF 4 ↑+CaF 2 +3H 2 O Section Four Halides 1. Properties and bond type 1) Bond type ○ 1 Same period ○ 2 Same family NaF MgF 2 AlF 3 SiF 4 PF 5 SF 6 Ionic type Covalent type 3 Same metal, different halogens eru ○4Same metal, different oxidation number 2) Properties ○ 1 Solubility NF 3 PF 3 AsF 3 SbF 3 BiF 3 Covalent type Transition Ionic type AlF 3 AlCl 3 AlBr 3 AlI 3 Ionic type Covalent type SnCl 2 ,PbCl 2 SnCl 4 , PbCl 4 Ionic type Covalent type 第 26 页 2006-02-22 26 △ 1 Most fluorides are insoluble. A few are soluble: AgF, PbF 2 , Hg 2 F 2 , fluoride of IA family (except Li) △ 2 Most halides (chlorine, bromine and iodine) are soluble. A few are insoluble: AgX, PbX 2 , Hg 2 X 2 , CuX ○ 2 Hydrolysis properties △ 1 Halides of active metals do not hydrolyze, but F - hydrolyzes △ 2 Halides of middle active metals hydrolyze by step, for example: AlCl 3 , FeCl 3 , MgCl 2 △ 2 Halides of nonmetals hydrolyze completely, for example: SiF 4 , PCl 3 , PCl 5 , BCl 3 , BF 3 (except CCl 4 , SF 6 ) △ 3 Some halides hydrolyze to form a precipitate or basic salt SbCl 3 +H 2 O → SbOCl↓ + 2HCl BiCl 3 +H 2 O → BiOCl↓ + 2HCl SnCl 2 +H 2 O → Sn(HO)Cl↓ + HCl Section Five Oxyacids 1. Type Chlorine, bromine and iodine form four series with formulae: HXO, HXO 2 , HXO 3 , and HXO 4 , in which the oxidation states of the halogens are Ⅰ,Ⅲ,Ⅴ,Ⅶ respectively HXO HXO 2 HXO 3 HXO 4 Hypohalous acid Halous acid Halic acid Perhalic acid Chlorous acid Bromous acid Iodous acid Hypochlorous acid Hypobromous acid Chloric acid bromic acid iodic acid Perchloric acid perbromic acid periodic acid 2. Chlorous acid and hypochlorites 1) Chlorous acid ○ 1 Preparation 第 27 页 2006-02-22 27 Cl 2 + H 2 O HClO + HCl 2Cl 2 + 2HgO + H 2 O 2HClO + HgO·HgCl 2 ↓ ○ 2 Properties △ 1 Weak acid, K a θ =4.0×10 -8 △ 2 Instability 2HClO ? →? light 2HCl +O 2 3HClO ? →? Δ HClO 3 + 2HCl △ 3 Oxidizing properties Page 318-319 ),( θθ BA EE : Elemental standard electrode potential diagrams ◇ 1 When HClO is an oxidant, the reductive product is Cl - ◇ 2 )/()/( ??? > ClClOEClHClOE BA θθ ◇ 3 In acid medium, HClO + Cl - → Cl 2 2) Hypochlorites ○ 1 Preparation Cl 2 +2NaOH NaClO+NaCl +H 2 O Cl 2 +Na 2 CO 3 NaClO+NaCl +CO 2 2Cl 2 +3Ca(OH) 2 Ca(ClO) 2 +CaCl 2 ?Ca(OH) 2 ?H 2 O+H 2 O ○ 2 Properties △ 1 Oxidizing properties yellow green -bright green -greyish violet 4)()( 2 43 3 ? ??→???→???→? ? ? ? ?? + blue CrOOHCrOHCrCr ClOOHOH 2Cr 3+ +3ClO - + 10OH - → 2CrO 4 2- +3Cl - +5H 2 O △ 2 Thermal stability 第 28 页 2006-02-22 28 3KClO ? →? Δ KClO 3 + 2KCl 3. Chloric acid and chlorates 1) Chloric acid ○ 1 Preparation 3HClO ? →? Δ HClO 3 + 2HCl Ba(ClO 3 ) 2 +H 2 SO 4 → 2HClO 3 +BaSO 4 ○ 2 Properties △ 1 Strong acid △ 2 Instability, when its content>40%: 3HClO 3 → 2O 2 ↑+Cl 2 ↑+HClO 4 +H 2 O △ 3 Oxidizing properties: strong oxidant 2HClO 3 +I 2 → 2HIO 3 +Cl 2 ↑ (5Cl 2 +I 2 +6H 2 O→ 2IO 3 - +10Cl - +12H + ) 2) Chlorates ○ 1 Preparation △ 1 3KClO ? →? Δ KClO 3 + 2KCl △ 2 3Cl 2 +6KOH → c°75 KClO 3 +5KCl+3H 2 O △ 3 Industrial method: electrolysis 2NaCl+2H 2 O ???? →? iselectrolys Cl 2 ↑+H 2 ↑+2NaOH 3Cl 2 +6NaOH ? →? Δ NaClO 3 +5NaCl+3H 2 ↑ NaClO 3 +KCl ?? →? cool KClO 3 +NaCl ○ 2 Properties △ 1 Thermal stability: KClO 3 >HClO 3 2KClO 3 ??? →? 2 MnO 3O 2 ↑ + 2KCl 第 29 页 2006-02-22 29 4KClO 3 ? →? Δ 3KClO 4 ↑ + KCl △ 2 Oxidizing properties ◇ 1 The solid of KClO 3 is a strong oxidant, when mixed with S, P, C in given proportion, if the mixture is stroked, explosion will happen. ◇ 2 In the solution of water, KClO 3 has oxidation ability after acidification ClO 3 - +6I - +6H + → 3I 2 +Cl - +3H 2 O ClO 3 - +Cl - +H + → Cl 2 + H 2 O BrO 3 - +Br - +H + → Br 2 + H 2 O IO 3 - +I - +H + → I 2 + H 2 O 4. Perchloric acid and perchlorates 1) Perchloric acid ○ 1 Preparation: KClO 4 +H 2 SO 4 ?? →? cool HClO 4 +KHSO 4 NaClO 3 +H 2 O ???? →? iselectrolys NaClO 4 +H 2 ↑ NaClO 4 +HCl→ HClO 4 +NaCl ○ 2 HClO 4 ? →? Δ 2Cl 2 ↑+7O 2 ↑+2H 2 O 2) Perchlorates Thermal stability: KClO 4 > KClO 3 HClO HClO 2 HClO 3 HClO 4 Weak acid Middle strong acid Strong acid Strongest acid Acidity increases Thermal stability increases (TSI) Oxidizing ability decreases (OAD) O A D MClO MClO 2 MClO 3 MClO 4 T S I 第 30 页 2006-02-22 30 Chapter Four Carbon Family and Boron Family (Group and Ⅲ)Ⅳ Central contents: 1. General properties of carbon family and boron family 2. Properties of carbonic acid and carbonates, silicic acid and silicates 3. Properties of oxides of tin (Sn) and lead (Pb), properties of their hydrates; the trends of these compounds 4. Reducing properties of Sn ( ) and oxidizing properties of Pb ( )ⅡⅣ 5. Properties and structure of diborane 6. Properties of boric acid and borates 7. Properties of AlCl 3 , Al 2 O 3 and Al(OH) 3 ; structure of AlCl 3 8. Concept of vitriol and diagonal rule 9. Know how to identify Al 3+ , Sn 2+ and Pb 2+ Section One General Properties of Carbon Family 1. Nonmetal→ metalloid → metal 2. Valence shell configuration: ns 2 np 2 3. Oxidation number 4. Type of crystal lattice Section Two Main compounds of Carbon Carbonic acid and carbonates 1. Properties of carbonic acid 1) Binary weak acid 2) Instability: H 2 CO 3 = CO 2 ↑+H 2 O 2. Properties of carbonates 1) Solubility: most acid carbonates are soluble; most normal carbonates are insoluble except sodium carbonate, potassium carbonate and ammonium carbonate △ 1 Insoluble carbonates Solubility: Acid carbonate > normal carbonate 第 31 页 2006-02-22 31 For example: S CaCO3 < S Ca(HCO3)2 CaCO 3 + H 2 O + CO 2 → Ca(HCO 3 ) 2 △ 2 Soluble carbonates Solubility: Acid carbonates < normal carbonates For example: S Na2CO3 > S NaHCO3 2) Hydrolysis △ 1 Normal carbonates CO 3 2- + H 2 O HCO 3 - + OH - HCO 3 - + H 2 O H 2 CO 3 + OH - △ 2 Acid carbonates HCO 3 - + H 2 O H 2 CO 3 + OH - HCO 3 - CO 3 2- + H + 3) M n+ + CO 3 2- △ 1 S hydrate < S carbonate → hydrate For example: Fe 3+ , Al 3+ , Cr 3+ 2Fe 3+ +CO 3 2- +3H 2 O→ 2Fe(OH) 3 ↓+3CO 2 ↑ 2Al 3+ +CO 3 2- +3H 2 O→ 2Al(OH) 3 ↓+3CO 2 ↑ △ 2 S hydrate ≈S carbonate → basic carbonate For example: Bi 3+ , Cu 2+ , Mg 2+ , Pb 2+ 2Cu 2+ +2CO 3 2- +H 2 O→ Cu 2 (OH) 2 CO 3 ↓+CO 2 ↑ △ 3 S hydrate >S carbonate → carbonate For example: Ca 2+ , Sr 2+ , Mn 2+ , Ba 2+ Ca 2+ + CO 3 2- → CaCO 3 ↓ 4) Thermal stability of carbonates Cation: polarization↑ thermal stability↓ △ 1 M n+ : 8 electron configuration Sample MgCO 3 CaCO 3 SrCO 3 BaCO 3 第 32 页 2006-02-22 32 (Same charge) M 2+ r↑ polarization↓ thermal stability↑ Decomposition temperature/K 675 1087 1371 1550 △ 2 Same electron configuration, M n+ : n↑ r↓ polarization↑ thermal stability↓, for example: Na 2 CO 3 is more stable than MgCO 3 , acid carbonates will be decomposed easily (H + r↓ polarization↑) △ 3 M n+ : 18, 18+2, 9~17 electron configuration, just like Fe 2+ , Cd 2+ , Pb 2+ etc. their carbonates are instability Stability: Normal carbonates > acid carbonates > carbonic acid 5) 2H + + CO 3 2- =H 2 CO 3 → CO 2 ↑+H 2 O CaCO 3 +2H + =Ca 2+ +CO 2 ↑+H 2 O Section Three Silicon and Its Main Compounds 1. Silicic acid: xSiO 2 ·yH 2 O x y Chemical formula Name 1 1 H 2 SiO 3 MetaSilicic acid 1 2 H 4 SiO 4 silicic acid 2 1 H 2 Si 2 O 5 Dimetasilicic acid 2 3 H 6 Si 2 O 7 Disilicic acid 3 2 H 4 Si 3 O 8 Trimetasilicic acid SiO 2 + 4HF → SiF 4 + 2H 2 O SiO 2 + 2NaOH → Δ Na 2 SiO 3 + H 2 O SiO 2 + Na 2 CO 3 → Δ Na 2 SiO 3 + CO 2 ↑ Properties: ○ 1 Binary weak acid: K 1 θ =2.5×10 -10 ; K 2 θ =1.6×10 -12 ○ 2 SiO 3 2- + 2H + → H 2 SiO 3 ↓ Na 2 SiO 3 +2HCl→ H 2 SiO 3 ↓+2NaCl 第 33 页 2006-02-22 33 SiO 3 2- +2NH 4 + +2H 2 O→ H 2 SiO 3 ↓+2NH 3 ·H 2 O 2. Silicates 1) Preparation SiO 2 + 2NaOH → Δ Na 2 SiO 3 + H 2 O SiO 2 + Na 2 CO 3 → Δ Na 2 SiO 3 + CO 2 ↑ 2) Solubility: most of silicates are insoluble except M 2 SiO 3 (M: alkali metals) 3) Hydrolysis: SiO 3 2- + H 2 O → HSiO 3 - + OH - HSiO 3 - + H 2 O → HSiO 3 + OH - 3) Different silicates of heavy metals have different color (p375) 4) Section Four Main Compounds of Tin and Lead 1. Properties of oxides and hydrates 1) Acid-base properties and trends Acidity SnO Sn(OH) 2 PbO Pb(OH) 2 SnO 2 Sn(OH) 4 PbO 2 Pb(OH) 4 Acidity Basicity Basicity 2) React with acid or base Pb 3 O 4 +4HNO 3 → 2Pb(NO 3 ) 2 +PbO 2 +2H 2 O M(OH) 2 + 2H + → M 2+ + 2H 2 O M(OH) 4 + 4H + → M 4+ + 4H 2 O M(OH) 2 + 2OH - → M(OH) 4 2- M(OH) 4 + 2OH - → M(OH) 6 2- 第 34 页 2006-02-22 34 2) α-stannic acid and β-stannic acid α-stannic acid: H 2 SnO 3 Sn 4+ +4OH - =Sn(OH) 4 ↓ → OH 2 ? H 2 SnO 3 SnO 2 +NaOH→ Na 2 SnO 3→ + H H 2 SnO 3 β-stannic acid: H 2 SnO 3 3Sn+4HNO 3 +H 2 O→ 3H 2 SnO 3 +4NO 2. Salts of tin and lead E A θ /V Sn 4+ 0.154 Sn 2+ -0.136 Sn PbO 2 1.46 Pb 2+ -0.126 Pb E B θ /V [Sn(OH) 6 ] 2- -0.93[Sn(OH) 4 ] 2- -0.136Sn PbO 2 0.28 PbO -0.580 Pb 1) Reducing properties of Sn (Ⅱ) 3[Sn(OH) 4 ] 2- +6OH - +2Bi 3+ =2Bi↓+3[Sn(OH) 6 ] 2- (Identification method for Bi 3+ ) SnCl 2 + 2HgCl 2 = SnCl 4 + Hg 2 Cl 2 ↓ SnCl 2 + Hg 2 Cl 2 = SnCl 4 + 2Hg↓ Bi:black Hg 2 Cl 2 :white Hg:black (Identification method for Hg 2+ and Sn 2+ ) 2)Oxidizing properties of Pb(Ⅳ): PbO 2 PbO 2 +4HCl(strong) → PbCl 2 +Cl 2 ↑+2H 2 O PbCl 2 +2HCl(strong) → [PbCl 4 ] 2- +2H + 5PbO 2 +2Mn 2+ +4H + → 2MnO 4 - +5Pb 2+ +2H 2 O E θ (O 2 /H 2 O)>E θ (Sn 4+ /Sn 2+ )>E θ (Sn 2+ /Sn) 2Sn 2+ + O 2 + 4H + → 2Sn 4+ + 2H 2 O Sn 4+ + Sn → 2Sn 2+ 3) Hydrolysis SnCl 2 + H 2 O → Sn(OH)Cl↓ + HCl 4) Solubility: Most salts of tin (Ⅱ) are soluble; most salts of lead (Ⅱ) are insoluble, but Pb(NO 3 ) 2 第 35 页 2006-02-22 35 and Pb(Ac) 2 are soluble, PbCl 2 can dissolve in hot water and PbSO 4 can dissolve in the solution of NH 4 Ac 2Pb 2+ +2CO 3 2- +H 2 O→ [Pb(OH)] 2 CO 3 ↓+CO 2 Pb 2+ + CrO 4 2- → PbCrO 4 ↓ Pb 2+ + 2I - → PbI 2 ↓ PbI 2 + 2I - → [PbI 4 ] 2- 3. Sulfides of tin and lead Solvent HCl HNO 3 Na 2 S Na 2 S 2 SnS √ √ × √ PbS √ √ × × SnS 2 × × √ × SnS 2 + Na 2 S → Na 2 SnS 3 Na 2 SnS 3 +2H + → H 2 SnS 3 → SnS 2 ↓+H 2 S↑ SnS + S 2 2- → SnS 3 2- → + H SnS 2 ↓+H 2 S↑ 3PbS+8HNO 3 → 3Pb(NO 3 ) 2 +3S↓+2NO↑+4H 2 O PbS+4HCl(strong)→ H 2 [PbCl 4 ]+H 2 S↑ Acidic/amphoteric sulfide + Na 2 S/ (NH 4 ) 2 S → salt of sulfoacid → + H sulfoacid → sulfide+H 2 S↑ Section Five General Properties of Boron Family 1. Nonmetal → metal 2. Valence shell configuration: ns 2 np 1 3. Oxidation number B Al Ga In Tl 0, +3 0, +1, +3 Section Six Main Compounds of Boron 1. Hydrides of boron: B n H n+4 , B n H n+6 B 2 H 6 (diborane) : 1) Preparation 第 36 页 2006-02-22 36 ○ 1 2BCl 3 + 6H 2 → B 2 H 6 + 6HCl ○ 2 4BCl 3 +3Li(AlH 4 )→ 2B 2 H 6 +3AlCl 3 +3LiCl 2) Structure 3) Properties: B 2 H 6 (g)+3O 2 (g)→ B 2 O 3 (s)+3H 2 O (g) B 2 H 6 (g)+6H 2 O(l)→ 2H 3 BO 3 (aq)+6H 2 ↑ B 2 H 6 + 2CO → 2[H 3 B← CO] B 2 H 6 + 2NH 3 → 2[H 3 B← NH 3 ] 2. Oxyacids of boron HBO 2 H 3 BO 3 xB 2 O 3 ·H 2 O 1) H 3 BO 3 ? C 0 169 HBO 2 ? C 0 300 B 2 O 3 2) Structure of H 3 BO 3 3) Properties of boric acid ○ 1 Boric acid is a monobasic acid and is quite weak, K a θ = 5.8×10 -10 ○ 2 H 3 BO 3 +3CH 3 OH→ B(OCH 3 ) 3 +3H 2 O H 3 BO 3 +3C 2 H 5 OH→ B(OC 2 H 5 ) 3 +3H 2 O 3. Borates 第 37 页 2006-02-22 37 H 3 BO 3 +NaOH ? →? ?1211:pH NaBO 2 +2H 2 O 4H 3 BO 3 +2NaOH ? →? < 6.9pH Na 2 B 4 O 7 +7H 2 O Na 2 B 4 O 7 ·10H 2 O borax Chemical formula: Na 2 B 4 O 5 (OH) 4 ·8H 2 O Na 2 B 4 O 5 (OH) 4 ·8H 2 O ?? →? ? C 0 400350 Na 2 B 4 O 7 → C 0 878 Na 2 B 4 O 7 (vitreous body) B 4 O 7 2- +7H 2 O 4 H 3 BO 3 + 2OH - Na 2 B 4 O 7 +H 2 SO 4 +5H 2 O→ 4H 3 BO 3 +Na 2 SO 4 Na 2 B 4 O 7 +CoO→ 2NaBO 2 ·Co(BO 2 ) 2 blue Na 2 B 4 O 7 +MnO→ 2NaBO 2 ·Mn(BO 2 ) 2 green 4. Halides of boron 1) Preparation B 2 O 3 +3CaF 2 +H 2 SO 4 → Δ 2BF 3 +3CaSO 4 +3H 2 O B 2 O 3 +3C+3Cl 2 ? →? > C 0 500 2BCl 3 +3CO 2) Properties: BF 3 BCl 3 BBr 3 BI 3 Gas Liquid Liquid Solid Hydrolysis: BX 3 +3H 2 O→ H 3 BO 3 +3HX BF 3 +HF → H[BF 4 ] Section Seve Main Compounds of Aluminum 1. Al 2 O 3 and Al(OH) 3 1) Al 2 O 3 preparation α- Al 2 O 3 : 4Al+3O 2 ? →? burning 2Al 2 O 3 γ- Al 2 O 3 : Al(OH) 3→ C 0 500 Al 2 O 3 +H 2 O 2) Al(OH) 3 preparation Al 3+ +3NH 3 ?H 2 O→ Al(OH) 3 ↓+3NH 4 + Al(OH) 3 +3HNO 3 → Al(NO 3 ) 3 +3H 2 O 第 38 页 2006-02-22 38 Al(OH) 3 +OH - → Al(OH) 4 - Al(OH) 3 +2NaOH(s) → melting 2NaAlO 2 +2H 2 O 2. AlCl 3 1) Structure 2) Properties AlCl 3 ?6H 2 O → Δ Al(OH) 3 ↓+3HCl+3H 2 O 3) Preparation: 2Al + 3Cl 2 → 2AlCl 3 4) Al 2 S 3 +6H 2 O→ 2Al(OH) 3 ↓+3H 2 S↑ 2Al 3+ +3CO 3 2- +3H 2 O→ 2Al(OH) 3 ↓+3CO 2 ↑ 3. Vitriol: M Ⅰ M Ⅲ (SO 4 ) 2 ·12H 2 O For example: KAl(SO 4 ) 2 ·12H 2 O KCr(SO 4 ) 2 ·12H 2 O r M( )Ⅰ >100pm: Na + ,K + ,Rb + ,Tl + ,NH 4 + r M( )Ⅲ :50-70pm: Al 3+ ,Fe 3+ ,Cr 3+ ,Co 3+ 4. Diagonal rule Li Be B C N Na Mg Al Si Element B Si React with KOH KBO 2 +H 2 H 2 SiO 3 +H 2 Acidity K θ ≈10 -10 K θ ≈10 -10 Oxyacids Stability Stable Stable 第 39 页 2006-02-22 39 Oxysalts of heavy metals Insoluble (color) Insoluble (color) Halides Hydrolysis (HBO 2 ) Hydrolysis (H 2 SiO 3 ) Si+ 2OH - + H 2 O → SiO 3 2- + 2H 2 ↑ 2B + 2OH - + 2H 2 O → Δ BO 2 - + 3H 2 ↑ Chapter Five Brief Summary of Main Group 1. Structure 1) HNO 3 , O 3 :∏ 3 4 , NO 3 - :∏ 4 6 B 2 H 6 :3c-2e; Al 2 Cl 6 :3c-4e 2) (p-d)π bond: H x RO y (y>x) H 2 SiO 3 , H 3 PO 4 , H 2 SO 4 , HClO 3 , HClO 4 3) Double bond: H x RO y : H 2 CO 3 , HNO 2 4) Single bond: H- O- X 2. Properties of some elements 1) Metallic, nonmetallic ○ 1 Same period, from left to right, metallic↓, nonmetallic↑ ○ 2 Same Group: from up to down, metallic↑, nonmetallic↓ 2) Inert electron pair effect 3) Diagonal rule 4) Properties of F 2 , Cl 2 , Br 2 , I 2 5) Properties of other simple substances (1) Main group metals (S area): ○ 1 A, A: Strong reducing propertiesⅠⅡ ○ 2 React with acids: most of them can replace hydrogen atom and give out hydrogen gas ○ 3 React with bases: most of them don’t react with bases, rare amphoteric elements can react with 第 40 页 2006-02-22 40 strong bases to form oxyacids and give out hydrogen gas, just like Al, Be, Ge, Sn etc. ○ 4 React with water: Alkali metals are so active that they can react with water to form bases and give out hydrogen gas (2) Main group nonmetals (P area) ○ 1 Most of these nonmetals have oxidizing properties and reducing properties ○ 2 Most of these nonmetals don’t react with water under the normal temperature except halogens, but red-hot carbon can react with water steam ○ 3 Simple substances of iodine, sulfur, phosphorus, carbon and boron can be oxidized by strong HNO 3 and strong H 2 SO 4 to form oxyacids, others do not react with acids ○ 4 Parts of nonmetals react with thick alkali: ◇ 1 Disproportionation reaction: X 2 +2OH - → X - +XO - +H 2 O 3X 2 +6OH - → Δ 5X - +XO 3 - +3H 2 O 3S+6OH - → Δ 2S 2- +SO 3 2- +3H 2 O 4P+3OH - +3H 2 O → Δ 3H 2 PO 2 - +PH 3 ↑ ◇ 2 Displacement reactions: Si, B Si +2OH - + H 2 O→ SiO 3 2- +2H 2 ↑ 2B+2OH - +2H 2 O → Δ 2BO 2 - +3H 2 ↑ ○ 5 React with H 2 O F 2 : displacement reaction Cl 2 , Br 2 , I 2 : disproportionation reactions 3. Hydrides AⅣ AⅤ AⅥ AⅦ CH 4 NH 3 H 2 O HF SiH 4 PH 3 H 2 S HCl 第 41 页 2006-02-22 41 GeH 4 AsH 3 H 2 Se HBr SnH 4 SbH 3 H 2 Te HI ○ 1 Melting point and boiling point increase from up to down, but HF, H 2 O and NH 3 are abnormal ○ 2 Thermal stability Substance NH 3 H 2 O HF Temperature/℃ 300 1200 3000 Decomposition 97% 0.02% - Same period: thermal stability increases from left to right Substance HF HCl HBr HI Decomposition temperature/ K - 3273 1868 1073 Same group: thermal stability decreases from up to down ○ 3 Reducing properties: Same period: Reducing properties decrease from left to right Same group: Reducing properties increase from up to down Reducing properties: HF< HCl< HBr< HI (HF and HCl don’t react with strong H 2 SO 4 , but HBr and HI react with strong H 2 SO 4 : SO 2 + Br 2 ; I 2 + H 2 S) ○ 4 Acidic/basic properties of aqueous solution: Same period: from left to right, acidity↑; NH 3 , H 2 O, HF Same group: from up to down, acidity↑; Acids H 2 S H 2 Se H 2 Te HF HCl, HBr, HI K θ 10 -7 10 -6 10 -4 Weak acid Strong acid, acidity↑ 4. Halides 1) Same period: From left to right, ionic → covalence 2) Same group: From up to down, the trend of forming ionic compounds increases 3) Different oxidation numbers of same metal, generally, higher oxidation number compounds are covalence while lower oxidation number compounds are ionic 4) Different halides of same metal of same oxidation number, F→ Cl→ Br→ I, ionic → covalence 第 42 页 2006-02-22 42 5) Hydrolysis 5. Sulfides Solve in following solution Soluble Dilute HCl Strong HCl HNO 3 Aqua regia Na 2 S ( NH 4 ) 2 S Na 2 S 2 Hydrolysis AⅠ NH 4 + A*Ⅱ ZnS MnS FeS CoS* NiS* PbS CdS SnS SnS 2 Sb 2 S 3 Sb 2 S 5 Bi 2 S 3 Ag 2 S CuS Cu 2 S As 2 S 3 As 2 S 5 CoS NiS HgS Hg 2 S K sp θ >10 -24 10 -25 ~10 -30 10 -30 ~10 -50 <10 -50 SnS 2 As 2 S 3 As 2 S 5 Sb 2 S 3 Sb 2 S 5 SnS Al 2 S 3 Cr 2 S 3 H 2 S 2 → H 2 S↑ + S↓ SnS + S 2 2- → SnS 3 2- 4FeS 2 +11O 2 → 2Fe 2 O 3 +SO 2 6. Oxides 1) Classification Oxidation number Type of compounds Examples -2 Normal oxides, oxyacids, oxysalts Na 2 O, CaO, H 2 O -1 Peroxides Na 2 O 2 , BaO 2 , H 2 O 2 -1/2 Hyperoxides KO 2 -1/3 Ozonides KO 3 0 O 2 , O 3 Properties: A: Acidity oxides, SO 2 , NO 2 ; B: Alkaline oxides, Na 2 O, CaO; C: Amphoteric oxides, BeO, Al 2 O 3 , As 2 O 3 ; D: Inert oxides, CO, NO 第 43 页 2006-02-22 43 Bond type: ionic and covalent 7. Hydrates 1) R-O-H model 2) Ionic potential (Φ) Φ=z/r (P 295) Φ 1/2 <7 7~10 >10 Properties Base Amphoteric Acid Zn(OH) 2 : Φ 1/2 =5.2 3) The strength of oxyacids: (1)Polyacids: K 1 θ : K 2 θ : K 3 θ ≈1:10 -5 :10 -10 (2) H n RO m [RO m-n (OH) n ]: H 3 PO 4 : PO(OH) 3 ; H 2 SO 4 : SO 2 (OH) 2 ; HNO3: NO 2 (OH) 2 m-n K 1 θ Strength of acids Examples 0 <10 -8 Weak acid HClO, H 3 BO 3 , H 3 AsO 3 1 10 -2 ~10 -4 Middle strong H 3 PO 4 , HNO 2 , H 2 SO 3 2 ≈10 3 Strong H 2 SO 4 , HClO 3 , HNO 3 3 ≈10 8 Very strong HClO 4 4) Thermal stability 5) Reducing/oxidizing properties 6) Classification (1) Reducing/oxidizing properties ○ 1 Oxidizing acid: HClO, HClO 3 ,, HClO 4 , strong H 2 SO 4 , H 2 S 2 O 8 , HNO 3 , H 3 AsO 4 ○ 2 Reducing acid: H 3 AsO 3 , H 2 S 2 O 3 , H 2 S ○ 3 H 2 SO 3 , HNO 2 ○ 4 H 3 PO 4 , H 2 SiO 3 , H 3 BO 3 (2) Solubility ○ 1 Insoluble: H 2 SiO 3 , H 2 SnO 3 ○ 2 Sparsely soluble: H 3 BO 3 ○ 3 Soluble: sulfuric acid, nitric acid, phosphoric acid etc. 第 44 页 2006-02-22 44 8. Oxysalts 1) Solubility 2) Hydrolysis 3) Carbonates 4) Thermal stability ○ 1 Same metal: if the oxyacid is more stable, the oxysalt will be more stable ○ 2 Normal salt > acid salt > acid ○ 3 Same acid radical: alkali metals >alkaline-earth metals > transition metals > ammonium Na 2 CO 3 CaCO 3 ZnCO 3 (NH 4 ) 2 CO 3 1800℃ 910℃ 350℃ 58℃ ○ 4 K 2 SO 4 > K 2 SO 3 ; KClO 4 >KClO 3 >KClO 2 >KClO ○ 5 CO 3 2- , NO 3 - , NH 4 + 5) Reducing/oxidizing properties 9. Important oxidizing agents and reducing agents oxidizing agents products Oxidizing agents products reducing agents products X 2 X - NO 2 - （H + ）NO X - X 2 ClO - （H + ） Cl - HNO 3 NO 2 ,NO,N 2 O,NH 4 + H 2 O 2 O 2 ClO - +Cl - +H + Cl 2 H 3 AsO 4 H 3 AsO 3 S 2 2- SO 2 ClO 3 - （H + ） Cl - NaBiO 3 （H + ） Bi 3+ SO 3 2- SO 4 2- ClO 3 - +Cl - +H + Cl 2 PbO 2 （H + ）Pb 2+ S 2 O 3 2- SO 4 2- I 2 : S 4 O 6 2- H 2 O 2 （H + ） H 2 O MnO 4 - （H + ）Mn 2- H 3 AsO 3 H 3 AsO 4 H 2 O 2 （OH - ） OH - Cr 2 O 7 2- （H + ） Cr 3+ SnCl 2 SnCl 4 第 45 页 2006-02-22 45 S 2 2- S 2- HgCl 2 Hg 2 Cl 2 Sn(OH) 4 2- Sn(OH) 6 2- SO 3 2- S Hg 2 Cl 2 Hg Fe 2+ Fe 3+ H 2 SO 4 （strong） SO 2 ,S,H 2 S Fe 3+ Fe 2+ Cr(OH) 4 - CrO 4 2- S 2 O 8 2- SO 4 2- Bi 3+ （OH - ）Bi（black） S 2- S,SO 2 ,SO 4 2- NO 2 - NO 3 - 10. Identification 11. Local name/popular name