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1、1.Hydrides belong to ionic Hydride(Except for Be,Mg)LiH NaH KH RbH CsH NaCl-90.4 -57.3 -57.7-54.3 -49.3-4411.1.White crystals;Poor thermal stabilityNote11.3 Compounds of S-Block elements1.2.Stong reducibility(1)Smelting of titanium:(2)Violent hydrolysis:1.3.Forming coordinated hydridesHydrolysis vio
2、lently in wet media2.Oxide2.1.Three types of oxidesNormal Oxides(O2-):Peroxides O22-):Superoxides(O2-):Stability:O2-O2-O22-Ozonides(O3-):paramagnetism Oxides of alkali metals:Normal oxides M2O Peroxides M2O2 Superoxides MO2 Ozonide MO32.2.OxideAlkali Metal Li Na K Rb CsBurning in air Li2O Na2O2 KO2
3、RbO2 CsO22.3.Preparation:Direct:Indirect:2.4.Peroxide s-block element except Be can form peroxide,M2O2,peroxide ion O22-:-O-O-2-Preparation of Na2O2:4Na+O2=2Na2O 2Na2O+O2=2Na2O2Properties of Na2O2:Reacting with water or dilute acid Na2O2+2H2O=H2O2+2NaOH Na2O2+H2SO4=H2O2+2Na2SO4 2H2O2=2H2O+O2 Strong
4、oxidizer Cr2O3+3 Na2O2=2Na2CrO4+Na2O MnO2+Na2O2=Na2MnO4 Reacting with CO2 2Na2O2+2CO2=2Na2CO3+O2 Peroxides of alkaline earth metals BaO2 BaO2+H2SO4=H2O2+BaSO4 Preparation of H2O2 in laboratory 2.5.Superoxide Under condition of excessive oxygen,K,Rb,Cs spontaneously burn to produce MO2.KO2 RbO2 CsO2
5、Orange Dark Brown Dark Yellow O2-orbital formula:KK(2s)2(2s*)2(2p)2(2p)4(2p*)3 Strong oxidizer:2MO2+2H2O=H2O2+O2+2MOH 4MO2+2CO2=2MCO3+3O22.6.Ozonide MO3 M=K,Rb,Cs 6KOH+4O3=4KO3+2KOHH2O+O2 Orangish-yellow3.Chemical properties(1)Reacting with H2O:(2)Reacting with CO2:(Li Cs intense)(Except for BeO)4.H
6、ydroxide 4.1.Physical propertiesThe solubility of metal hydroxides of the same main group gradually increases from top to bottom.The solubility of hydroxide of alkaline earth metal is less than that of hydroxide of corresponding alkaline metal.However,Be(OH)2 and Mg(OH)2 hardly dissolve in water.4.2
7、.Change rule of alkalinity Be(OH)2 is amphoteric,and others are strongly alkaline or moderately alkaline.Dissociation mode of ROH:RO+H+ROH R+OH Acidic dissociation Alkaline dissociation LiOH NaOH KOH RbOH CsOHmoderately strong strong strong strong strong Be(OH)2 Mg(OH)2 Ca(OH)2 Sr(OH)2 Ba(OH)2amphot
8、eric moderately strong strong strong strong(Except BeO)Properties:(1)Easily absorbing water and dissolving (2)Solubility and alkalinity(toward arrow)solubility and basicity increase graduallySolubilityMOH easily dissolves in water and releases heat.Solubility of hydroxides of alkaline earth metals(2
9、0)Increased solubilityLiOHNaOHKOHRbOHCsOHBe(OH)2Mg(OH)2Ca(OH)2Sr(OH)2Ba(OH)2Enhanced alkalinityIncreased solubilityChange rule of alkalinityEnhanced alkalinity Increased solubilityEnhanced alkalinity and increased solubilityHalides,Nitrates,Sulfates,Carbonates5.Important salts and their properties5.
10、1.Crystal type:Most of them are ionic crystals,but halides of alkaline earth metals present certain covalency.Be2+has strong polarization,and BeCl2 belongs to a covalent compound.BeCl2 MgCl2 CaCl2 SrCl2 BaCl2 M.P./405 714 782 876 962 Ionicity increases5.2.Usually colorless or white5.3.Solubility:Sal
11、ts of alkali metals present generally high solubility in water;while,salts of alkaline earth metals,except for halides and nitrates,show relatively small solubility.5.4.Thermal stability:Relatively strong 6.Salts of alkali metals and alkaline earth metalsImportant salts6.1.Halide NaCl KCl MgCl2 CaCl
12、2 etc.(1)NaCl is the main component of eatable salt,while other components are a small amount of MgCl2 and CaCl2,etc.Mg2+and Ca2+are removed by lime-sodium carbonate treatment.(2)MgCl2 Main sources:Carnallite(KClMgCl2 6H2O)and sea Anhydrous MgCl2 can be prepared in stream of dried HCl via dehydratio
13、n of MgCl2 6H2O.(3)CaCl2 Anhydrous CaCl2 can be obtained by directly heating and dehydration of CaCl2 6H2O,which has very strong water-absorbing capacity and therefore is a common desiccant.(4)BaCl2 BaCl2 2H2O6.2.Carbonates(1)Water solubility Carbonates of alkali metals,except for Li2CO3,are soluble
14、 in water.Carbonates of alkaline earth metals,except BeCO3,are difficult to dissolve in water,whereas the basic carbonates are soluble in water.(2)pH of aqueous solution The soluble carbonates of alkali and alkaline earth metals are hydrolyzed easily in aqueous solution to make them alkaline.CO32+H2
15、O =HCO3+OH(3)Thermal stability The carbonates of alkali metals have higher stability,while the carbonates of alkaline earth metal have lower thermal stability.6.3.Nitrates The solubility of nitrates of alkali and alkaline-earth metals is high.Main components of black powder:KNO3 The main reaction that occurs when black powder explodes:2KNO3+3C+S=K2S+N2+3CO24KNO3+6C+2S=K2S2+K2CO3+CO+2N2+4CO210KNO3+16C+5S=3K2SO4+4K2CO3+K2S2+8N2+12CO2