无机化学无机化学英文PPT (21).ppt

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1、 Silane(SinH2n+2),The simplest silane:SiH4(1)Spontaneous combustion:(2)Strong reducibility:(3)Hydrolysis:(4)Poor thermal stability:Property：Silicon dioxide SiO2-SilicaAmorphous silicon:quartz glass,diatomaceous earth,flintCrystalline silicon:natural quartz,atomic crystalPure silica:crystalQuartz wit

2、h impurities:agate,amethystCrystalQuartz saltObsidianAmethystOnyxAgateCairngormBloodstoneJasperOpalAgateCrystalStructure:Silicon adopts sp3 hybridization to form silicon-oxygen tetrahedra with oxygenSilica tetrahedron Diamond Silicon dioxide Property(1)Interact with acid(2)Interact with HF Silicic a

3、cid and silicate H4SiO4 Orthosilicic acidSilicic acids H2SiO3 Metasilicic acid,binary weak acid xSiO2yH2O Polysilicic acidPreparation：Gelatinous silicateSilica gel-H2O Preparation of silica gel：add acid to Na2SiO3 solution Ssilicic colloid solution and saltaginggelhot water washing 100 C dryingporou

4、s silica gel24 h The composition of silica gel belongs to silica,but the silica tetrahedron inside the system is disorder,which can be used as adsorbent after activated at 300 C.The silica gel impregnated with CoCl2 is color-changing silica gel,and the degree of water absorption of silica gel is det

5、ermined according to the change from blue to red.Anhydrous CoCl2 CoCl26 H2OSilicates are complex in structure and are generally written as oxides.Sodium silicate:Na2OnSiO2Zeolite:Na2O Al2O3 2SiO2 nH2OChain polysilicate anions:Many silicon-oxygen tetrahedrons are connected in infinite chains,and two

6、adjacent silicon-oxygen tetrahedrons share one oxygen atom.silicic acid anionic chains are distributed with positively charged metal ions,which are held together by electrostatic attraction.These silicates have fibrous structures.云母 KMg3(OH)2Si3AlO10Lamellar polysilicate anions:Each silicon-oxygen t

7、etrahedron is connected to three neighboring silicon-oxygen tetrahedron by sharing three oxygen atoms,forming a lamellae structure.The lamellae are held together by the electrostatic attraction of metal ions.Network polysilicate anions:Silicon-oxygen tetrahedrons share four oxygen atoms to form vari

8、ous three-dimensional network structures.If aluminum atoms in a silicon-oxygen tetrahedron is instead of silicon atoms,the aluminosilicate network skeleton could be formed with a negative charge,so,there must be cation to balance the negative charge of skeleton,Such as zeolite,is used as a catalyst

9、or catalyst carrier.Solubility:Na2SiO3,K2SiO3Insolubility:Most are insoluble in water and have characteristic colorsSilicateThe water garden Silicate(x SiO2 y H2O)x=1，y=1，H2SiO3 Metasilicate x=1，y=2，H4SiO4 Orthosilicate x=2，y=1，H2Si2O5 Two metasilicate x=2，y=3，H6Si2O7 The focal silicate(1)Solubility

10、：Except IA silicate,others are insoluble.In general,the soluble Na2SiO3 is used as sodium silicate,or foam alkali.The plug during the long-term storage of NaOH,Na2CO3 bottles is used by rubber,not glass.(2)Hydrolysis of silicate:The hydrolysis of SiO32-is alkaline,which can be completely hydrolyzed

11、if NH4+or CO2 is added：SiO32 +2NH4+2H2O H2SiO3+2 NH3H2O 2NH3+2H2O4.Halides of silicon:SiX4 SiF4 SiCl4 SiBr4 SiI4State of aggregation:g l l sMolecular weight:small larger :low highHydrolysis:（Fluosilicic acid）Dissolve and boiling pointEmery(SiC):(2)To identify Bi3+4 2Bi(OH)3+3Sn(OH)42-=3Sn(OH)62-+2Bi

12、 blackThe reducibility of SnCl2:In the acid or base system,the reduced ability is relative strong2 HgCl2 +SnCl2+2 HCl Hg 2Cl2(白白)+H2SnCl6Hg2Cl2 +SnCl2 H2SnCl6 +2 Hg(黑黑)These two reactions could be used to identify Sn2+or to detect Hg2+E A/V Sn4+Sn2+Sn E B/V Sn(OH)62 HSnO2 Sn 0.15-0.14 -0.96 -0.91whi

13、teblack A small amount of HCl and Sn particle(as protection agent)should be added.Preparation of SnCl2 aqueous solution Easy to hydrolysis：SnCl2 +H2O Sn(OH)Cl+H+Cl SnCl4 +2 Cl SnCl62 PbI2+2 I PbI42ThinkingQuestion 5.Write the molecular structural formula of carbon monoxide,carbon dioxide and carboni

14、c acid,and describe their structural characteristics.Question 6.Why the thermal stability of alkali metal carbonate is higher than that of its alkali metal acid type carbonate,while the solubility of alkali metal carbonate is lower than that of its alkali metal acid type carbonate.Question 7.How to identify Sn2+and Pb2+in solution?Question 8.Why do you add HCl acid and Sn particles when preparing SnCI2 solution?Otherwise,what will happen?and write the reaction equation.Also write the chemical reaction equation for preparation of aluminum when using bauxite as the raw material.