北京化工大学：《无机化学》课程电子教案（课件讲稿，2015）Chapter 16 The elements of oxygen family

§16 The elements of oxygen family 16.1 Outline on oxygen family 16.2 Oxygen and the related compounds 16.3 Sulfur and the related compounds

§16 The elements of oxygen family 16.3 Sulfur and the related compounds 16.2 Oxygen and the related compounds 16.1 Outline on oxygen family

16.1 Outline on oxygen family (VIA) element oxygen sulfur selenium tellurium polonium element symbol 0 S Se Te Po radioactive character nonmetal quasi-metal metal natural existing elemental substance Accrete(共生)with sulfide of heavy metals form or mineral valence electron 2s22p4 3s23p4 4s24p4 5s25p4 6s26p4 configuration electronegativity 3.44 2.58 2.55 2.10 2.0 oxidation number -2,(-1) ±2,4,6 ±2,4,6 2,4,6 2,6 red Se crystal type molecular (molecular) chain like metallic gray Se (chain like)

16.1 Outline on oxygen family oxygen sulfur selenium tellurium polonium element symbol (VIA) O S Se Te Po character nonmetal quasi-metal radioactive metal natural existing form elemental substance or mineral Accrete(共生) with sulfide of heavy metals valence electron configuration 2s 2 2p4 3s2 3p4 4s 2 4p4 5s 2 5p4 6s 2 6p4 electronegativity 3.44 2.58 2.55 2.10 2.0 oxidation number -2, (-1) ±2,4,6 ± 2 ,4,6 2 ,4,6 2,6 crystal type molecular red Se (molecular) gray Se (chain like) chain like metallic element

Sulfur 夏威夷劳厄火山裂缝喷 天然硫晶体 气孔附近的天然疏沉积

夏威夷劳厄火山裂缝喷 气孔附近的天然硫沉积 天然硫晶体

Se Te Covalent hydride H2O H2S H2Se H,Te chemical reactivity: low high stability: high low acidity: weak strong mp and bp: the highest low high

H2O H2S H2Se H2Te chemical reactivity： low high stability： high low acidity： weak strong mp and bp： the highest low high Se Te Covalent hydride

16.2 Oxygen and the related compounds 1.Oxygen (O2) 0:1S22S22P4 Molecular orbital configuration: G1s)2(G1s)2(o2s)2(G2s)2(G2p)2(π2p)4(π2p)2 :OO:πTwo2-center--3-electronπbonds Under acidic condition:strong oxidizing agent 02+4H+4e=2H,0E6=1.229V basic condition: 02+2H20+4e=40HEe=0.401V

basic condition： 2 2 4 2 2 2 2 2 2 2s 2 1 2 1 ( ) ( ) ( ) ( ) ( ) (π ) (π p ) * p p s * s * σ s σ σ σ σ 1. Oxygen ( O2 ) Molecular orbital configuration： 16.2 Oxygen and the related compounds O      O      Under acidic condition：strong oxidizing agent O 2H O 4e 4OH E = 0.401V - - 2 2 + + O 4H 4e 2H2O E =1.229V - 2 + + + 3  2 Two 2-center-3-electron  bonds O: 1S22S22P4

2.Ozone (O3):one of the allotropes of oxygen Structure: The central oxygen:sp2 hybridization bond angle:1170 SO: W=1.8×10-30Cm a polar elemental substance (a)3个p轨道 Properties:unstable 203=302△H=-285.4kJ.mol ·oxidizing ability 03+2H+2e-02+H,0ER=2.075V 03+H,0+2e-02+20HE9=-1.247V 03+2I+2H+→I2+02+H2O

2. Ozone (O3 )：one of the allotropes of oxygen O 2I 2H I 2 O2 H2 O - 3 + +  + + + Structure： The central oxygen: sp2 hybridization bond angle：117o μ =1.8×10-30C•m Properties：• unstable • oxidizing ability a polar elemental substance 2O3 3O2 -1 Δ r H m = -285 .4kJ •mol O 2H 2e O2 H2O A 2.075V - 3 + + + = + E O H O 2e O2 2OH B 1.247V - 3 2 + + + = - E 4 Π3

3.Hydrogen peroxide(H2O2) H Structure: 9>0 149pm O:sp3 hybridization 9>0 Properties:.weak acidity H,02=H0,+HK9=2.0X1012,KH=1025 H2O2+Ba(OH)2-BaO2+2H2O ·unstable 2H202=2H,0+02△H=-196 kJ.mol

3. Hydrogen peroxide (H2O2 ) • unstable O O H H 149pm 97 o 97 o 97pm 94 o Properties：• weak acidity -1 2H2O2 2H2O + O2 = -196kJmol △ rHm H2O2 + Ba(OH)2 BaO2 + 2H2O H O HO H 2.0 10 ， =10 - -12 -25 2 2 2 + = ×  + K 1 K 2 Structure： O: sp3 hybridization

·redox property in acidic 020.6945VH021.763VH0 solution: H202+2Fe2++2Ht→2Fe3++2H,0 oxidant 4H202+PbS(s,黑)→PbS04(s,白+4H2O reducer 5H,02+2MnO4+6H→2Mn2++502+8H,0 in basic H02+H,0+2e=3OH,E8=0.867V solution 3H,O,+2Cr(OH)a +20H>2CrO+8H,O we can see the oxidation ability of H2O2 is strong and reduction ability is weak;So,it can be used as bactericide

we can see the oxidation ability of H2O2 is strong and reduction ability is weak；So, it can be used as bactericide. 3H O 2Cr(OH) 2OH 2CrO 8H2 O 2- 4 - - 2 2 + 4 +  + H O 2Fe 2H 2Fe 2H2 O 2 3 2 2 + +  + + + + in acidic solution： O2 0.6945V H2 O2 1.763V H2 O • redox property HO H O 2e 3OH , 0.867V - - 2 - 2 + + E = B 5H O 2MnO 6H 2Mn 5O2 8H2 O - 2 2 2 + 4 +  + + + + 4H2 O2 + PbS(s,黑) PbSO4 (s,白) + 4H2 O in basic solution： oxidant reducer

16.3 Sulfur and related compounds 1.Elemental sulfur:a few allotropic forms rhombic sulfur monoclinic sulfur plastic sulfur (斜方硫) (单斜硫) (弹性硫) density/g'cm3 2.06 1.99 color yellow buff fast cooling of liquid (浅黄) sulfur heated above stability 94.5℃ 190℃ Structure: a puckered Sa ring structure S:sp3 hybridization for both斜方硫and单斜硫

rhombic sulfur monoclinic sulfur plastic sulfur (斜方硫) (单斜硫 ) (弹性硫) density/gcm-3 2.06 1.99 color yellow buff fast cooling of liquid (浅黄) sulfur heated above stability 94.5℃ 190℃ 1. Elemental sulfur: a few allotropic forms 16.3 Sulfur and related compounds Structure： S：sp3 hybridization for both 斜方硫 and 单斜硫 a puckered S8 ring structure

rhombic sulfur monoclinic sulfur The formation of plastic sulfur S(斜方)945SS(单斜)190℃→弹性硫

rhombic sulfur monoclinic sulfur The formation of plastic sulfur S(斜方) 94.5 S(单斜) 190 C  弹性硫 oC